WO2004074051A1

WO2004074051A1 - A safety arranement

Info

Publication number: WO2004074051A1
Application number: PCT/SE2004/000130
Authority: WO
Inventors: Lennart Haglund
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2003-02-20
Filing date: 2004-02-02
Publication date: 2004-09-02
Anticipated expiration: 2005-08-20
Also published as: GB0303915D0; DE112004000307T5; JP2006518305A; KR101122190B1; KR20050114623A; CN1774358A; CN100384665C; GB2398545A; JP4555281B2

Abstract

A safety arrangement to lift the rear part of the hood or bonnet of a motor vehicle, the safety arrangement comprising a hinge connecting the rear part of the hood or bonnet to the main part of the vehicle to permit the front part of the hood or bonnet to be opened, the hinge having: a first hinge part and a second hinge part, one of said hinge parts being secured to or formed integrally with the main part of the vehicle and the other hinge part being secured to or formed integrally with the rear part of the hood or bonnet; a hinge arm pivotally connected at one end to said first hinge part and connected at its other end to said second hinge part, said connection between said other end of the hinge arm and said second hinge part comprising a moveable pivot to allow rotational movement of the hinge arm relative to said second hinge part, said moveable pivot being moveable with respect to said second hinge part between a first position and a second position, the second position being spaced rearwardly of the first position; said hinge arm being releasably connected to said second hinge part such that said pivot is located in located in said first position, and there being provided a release mechanism to release said releasable connection to allow the rear part of the hood and bonnet to be lifted, wherein said moveable pivot moves from said first position towards said second position as the rear part of the hood or bonnet is lifted.

Description

"A SAFETY ARRANGEMENT"

THE PRESENT INVENTION relates to a safety arrangement, and more particularly relates to a safety arrangement for a motor vehicle to provide protection for a pedestrian struck by the vehicle in an accident situation.

If a pedestrian is struck by a vehicle in an accident situation, the pedestrian may be thrown in such a way that the head or torso of the pedestrian impacts with the hood or bonnet of the motor vehicle. The hood or bonnet of the motor vehicle may thus deform as a consequence of such impact, but, if the hood or bonnet is closed, then the hood or bonnet may only deform by a very short distance before the underside of the hood or bonnet will engage with part of the engine located under the hood or bonnet.

Consequently, it is has been proposed to provide a mechanism which, in response to the sensing of an impact with a pedestrian, partially raises the hood or bonnet of the vehicle. Thus, when the pedestrian impacts with the hood or bonnet, the hood or bonnet is able to deform over a substantial distance before the underside thereof engages with the engine. During this extensive deformation of the hood or bonnet, the head or torso of the pedestrian may be decelerated appropriately, relative to the vehicle, without substantial injury arising. Various arrangements have been proposed previously to raise the rear part of the hood or bonnet of a vehicle in response to an accident situation involving an impact with a pedestrian. Typically, however, a bonnet or hood must be raised for servicing purposes about hinges provided at the rear part of the bonnet, thereby allowing the front part of the bonnet to be opened upwardly so that easy access can be gained to the engine compartment from the front of the vehicle. Consequently, it has been necessary to devise special hinge arrangements which firstly enable the bonnet to be lifted from the front in the normal way, about a pivot axis defined at the rear of the bonnet or hood by the hinges (thereby allowing easy servicing of the vehicle), and which additionally permit the rear part of the bonnet to be raised in an accident situation. The front region of the bonnet is provided with a locking mechanism which releasably locks the front part of the bonnet with respect to the front part of the chassis of the motor vehicle. The locking mechanism can thus be released to allow the bonnet to be opened from the front to allow servicing.

However, lifting the rear of the bonnet causes a pivoting movement of the bonnet around the front locking mechanism. It is common for the front locking mechanism to be located slightly behind to the forward most edge of the hood or bonnet so that, when the hood is bonnet is located in its normal closed position, the forward most edge of the hood or bonnet is located immediately adjacent the front part of the vehicle's bodywork to ensure that the "panel-gap" is as small as possible, thereby avoiding an unsightly appearance. When the rear part of the hood or bonnet of certain prior-proposed safety arrangements of the type above is lifted, then the result is that the forward most part of the hood or bonnet pivots around the locking mechanism and hence moves downwardly and sometimes forwardly if the point about which the front of the bonnet pivots is located significantly below the hood or bonnet. This can cause the forward most edge of the hood or bonnet to impinge against the forward part of the vehicle's bodywork which can result in permanent deformation of the hood or bonnet and/or the bodywork. This is disadvantageous in the event of an inadvertent actuation of the safety device to lift the rear part of the hood or bonnet, because even if the hood or bonnet can be re-set into its normal position, it will still be deformed which is unsightly and hence disadvantageous.

The present invention seeks to provide an improved safety device of the type intended to allow the rear part of a hood or bonnet to be lifted in response to an accident situation involving an impact with a pedestrian.

According to the present invention, there is provided a safety arrangement to lift the rear part of the hood or bonnet of a motor vehicle, the safety arrangement comprising a hinge connecting the rear part of the hood or bonnet to the main part of the vehicle to permit the front part of the hood or bonnet to be opened, the hinge having: a first hinge part and a second hinge part, one of said hinge parts being secured to or formed integrally with the main part of the vehicle and the other hinge part being secured to or formed integrally with the rear part of the hood or bonnet; a hinge arm pivotally connected at one end to said first hinge part and connected at its other end to said second hinge part, said connection between said other end of the hinge arm and said second hinge part comprising a moveable pivot to allow rotational movement of the hinge arm relative to said second hinge part, said moveable pivot being moveable with respect to said second hinge part between a first position and a second position, the second position being spaced rearwardly of the first position; said hinge arm being releasably connected to said second hinge part such that said pivot is located in said first position, and there being provided a release mechanism to release said releasable connection to allow the rear part of the hood or bonnet to be lifted, wherein said moveable pivot moves from said first position towards said second position as the rear part of the hood or bonnet is lifted.

Preferably, said other end of the hinge arm is connected to said second hinge part via a connecting element located between the hinge arm and second hinge part, said connecting element being pivotally connected to said other end of the hinge arm by said moveable pivot and pivotally connected to said second hinge part by a second pivot, such that the connecting element pivots about said second pivot during lifting of the rear part of the hood or bonnet, thereby moving the moveable pivot rearwardly.

Advantageously, said second hinge part is secured to or formed integrally with the main part of the motor vehicle.

Conveniently, said moveable pivot is slideably received within an elongate slot formed on said second hinge part.

Preferably, said second hinge part is secured to or formed integrally with the rear part of the hood or bonnet.

Advantageously, the safety arrangement comprises a tether connected at one end to one of said hinge parts, and connected at its other end to the other hinge part or to the hinge arm.

Advantageously, the safety arrangement further comprises an elongate support arm, one end of the support arm being pivotally connected to said hinge arm at a position between its two ends, and the other end of the support arm being pivotally connected to said second hinge part at a position spaced rearwardly of said moveable pivot.

Conveniently, said support arm has a length effective to limit the degree of rotational movement between said hinge arm and said second hinge part during lifting of the rear part of the hood or bonnet.

Preferably, said safety mechanism comprises a tether connected at one end to one of said hinge parts and connected at its other end to said support arm.

Preferably, said release mechanism is acruable by a pyrotechnic charge.

Advantageously, said release mechanism comprises a moveable locking pin carried by said second hinge part, the locking pin being received within a locking aperture provided on the hinge arm.

Conveniently, the safety arrangement further comprises a lifting element located beneath the rear part of the hood or bonnet and actuable to lift the rear part of the hood or bonnet.

Preferably, said release mechanism is actuable in response to actuation of said lifting element.

Alternatively, said lifting element is actuable in response to actuation of said release mechanism.

Preferably, the safety arrangement further comprises a locking arrangement to releasably lock the front part of the hood or bonnet in a closed position, the locking arrangement comprising a locking element carried by the front part of the hood or bonnet, and a locking mechanism provided on the main part of the vehicle to releasably engage said locking element, whilst allowing downwards movement of the locking element relative to the main part of the vehicle.

Advantageously, said locking mechanism is configured to releasably engage said locking element whilst allowing sliding movement of said locking element relative to said mechanism.

Conveniently, said locking mechanism comprises a plate having a slot formed therein, said locking element being releasably retained within said slot for sliding movement therein.

Preferably, said locking element is mounted to the front part of said hood or bonnet for deflection relative to said hood or bonnet.

So that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic sectional view through the front part of a hood or bonnet of a motor vehicle, illustrating the hood or bonnet in its normal position relative to a front part of the vehicle's bodywork;

Figure 2 is a view corresponding generally to that of Figure 1, but illustrating the hood or bonnet in an alternate position in which the rear part of the hood or bonnet has been lifted, to show the technical problems associated with prior proposed safety devices;

Figure 3 is a view corresponding generally to that of Figure 2, but illustrating the hood or bonnet in a position in which the rear part of the hood or bonnet has been lifted and the hood or bonnet moved backwards slightly away from the front part of the motor vehicle's bodywork;

Figure 4 is a schematic view illustrating a safety arrangement in accordance with the present invention installed under the rear part of a hood or bonnet;

Figure 5 is an enlarged schematic view of the safety arrangement illustrated in Figure 4;

Figure 6 is a perspective view of a hinge arrangement forming part of the present invention, showing the hinge arrangement in an open, actuated configuration;

Figure 7 is a perspective view of the hinge arrangement illustrated in

Figure 6, showing the hinge arrangement in a normal, closed, configuration;

Figure 8 is a schematic view generally corresponding to that of Figure 5, but illustrating the hinge arrangement opened in a manner to allow the front part of the hood or bonnet to be opened;

Figure 9 is a perspective view corresponding generally to that of Figure 7, but illustrating the hinge arrangement in the configuration illustrated in Figure 8; Figure 10 is a schematic illustration of the safety arrangement of the present invention in its actuated configuration;

Figure 11 is a view corresponding generally to that of Figure 4, but illustrating the safety arrangement in its actuated configuration, having lifted the rear part of the hood or bonnet;

Figure 12 is a schematic illustration of a hinge of an alternative hinge arrangement forming part of another embodiment of the present invention;

Figure 13 illustrates a locking arrangement provided at the front of the hood or bonnet, in a normal configuration;

Figure 14 illustrates the locking arrangement of Figure 13 from below;

Figure 15 illustrates the locking arrangement of Figures 13 and 14 in an alternate configuration, adopted when the rear part of the hood or bonnet has been moved upwardly and rearwardly;

Figure 16 is a view of an alternative configuration of locking mechanism provided at the front part of the hood or bonnet;

Figure 17 illustrates the locking arrangement of Figure 16 from below; and

Figure 18 illustrates the locking arrangement of Figures 16 and 17 in an alternate configuration in which the rear part of the hood or bonnet has been move upwardly and rearwardly. Referring initially to Figure 1, there is illustrated, in schematic form, the front region of a hood or bonnet 1 of a motor vehicle. The hood or bonnet 1 is illustrated in its normal, closed, position in which the forwardmost edge 2 of the hood or bonnet 1 is located substantially adjacent and flush with a forwardmost part of the motor vehicle's bodywork 3, located in front and below the hood or bonnet 1. It would be seen that the front edge 2 of the hood or bonnet 1 is spaced from the bodywork 3 to define a relatively small "panel- gap" 4 therebetween.

Extending downwardly from the front region of the hood or bonnet 1 is a locking loop 5 which is engaged and prevented from upwards movement by a releasable catch element 6 in a manner known er se.

Figure 2 illustrates the bonnet or hood 1 in a position in which the rear part of the bonnet or hood 1 has been lifted vertically, for example by a prior- art type of safety arrangement so as to move the main part of the hood or bonnet away from the engine block located therebelow, thereby providing a sufficient gap to allow the hood or bonnet to deform when hit by a pedestrian, thereby absorbing energy from the impact with the pedestrian. It will be seen from Figure 2 that the front end of the hood or bonnet 1 pivots about the locking catch 6 and therefore, because the forwardmost edge to the hood or bonnet 1 extends forwardly from the locking catch 6, the forwardmost edge 2 is caused to move further forward and downwardly as the rear part of the hood or bonnet 1 is lifted. Because of the small panel gap 4, the forwardmost edge 2 engages the front part of the bodywork 3, which can cause the forward edge 2 and/or the bodywork 3, to become permanently deformed which, as described hereinbefore, is disadvantageous. It is therefore desirable to seek to achieve movement of the hood or bonnet 1 towards a position generally as illustrated in Figure 3, as the rear part of the hood or bonnet 1 is lifted. In Figure 3, it will be seen that the entire hood or bonnet 1 has been moved backwards relative to the structure of the vehicle as its rearmost part is lifted. This allows the forwardmost edge 2 of the hood or bonnet 1, to move downwardly, whilst remaining clear of the front part of the bodywork 3, thereby avoiding damage to the front edge 2 or the bodywork 3. The safety arrangement of the present invention is configured to achieve this type of movement of the hood or bonnet 1 in response to a signal indicative of an imminent collision with a pedestrian.

Turning now to consider Figure 4, there is illustrated a safety arrangement 7 in accordance with a first embodiment of the present invention, installed underneath the rear part of the hood or bonnet 1. The illustrated safety arrangement 7 comprises a lifter 8 in the form of a piston which is actuable upon receipt of an appropriate signal from a crash sensor (not shown) so as to extend in length (for example as illustrated in Figure 10), thereby driving the rear part of the hood or bonnet 1 upwardly. However, the piston could be replaced with a lifter of any other convenient form such as, for example, a bellows arrangement or some form of inflatable air bag arrangement.

The safety arrangement also comprises a pair of hinges 9 (only one such hinge being illustrated), located underneath the rear part of the hood or bonnet and mounted between the hood or bonnet and the main part of the motor vehicle at either side of the hood or bonnet. One of the hinges 9 is illustrated most clearly in Figure 6. The hinge 9 illustrated in Figure 6 is designed to be installed under the left hand side of the hood or bonnet and is shown viewed from the rear and outer left-hand side. A corresponding ("mirror-image") hinge is installed under the right-hand side of the hood or bonnet.

The hinge 9, comprises a lower hinge part 10, and upper hinge part 11 and a hinge arm 12, interconnecting the two hinge parts 10,11. The hinge part 10 has a generally elongate vertical side plate 13 carrying an inwardly directed mounting flange 14 from its lowermost edge. The inwardly directed flange 14 has a pair of mounting apertures 15 formed therethrough to allow the lower hinge part 10 to be securely mounted, for example by a pair of bolts, to the main part of the motor vehicle, at a position below the rear part of the hood or bonnet 1.

As illustrated most clearly in Figure 8, the side plate 13 of the lower hinge part 10 is generally rectangular in form, but the forwardmost part of the side plate 13 has an upwardly directed extension defining a part-circular uppermost edge 16. The rear part of the side plate 13 extends past the mounting flange 14 and carries a release mechanism 17 which is mounted to the side plate via a mounting aperture formed through the side plate. The release mechanism 17 has a locking spigot 18 which is initially directed outwardly towards the side of the vehicle and is operable by a pyrotechnic charge so as to move inwardly (as shown in Figure 6) upon actuation of the pyrotechnic charge. The purpose of locking spigot 18 will become clear hereinafter.

An elongate, but relatively short connecting element 19 is pivotally mounted to the outer side of the side plate 13 so as to be pivotally moveable relative to the side plate 13 about a pivot 20 which is coincident with the centre of the circle defining the part-circular edge 16. The other end of the connecting element 19 is pivotally connected (at 21) to the forwardmost end of the hinge arm 12. Connection between the forwardmost end of the hinge arm 12 and the connecting element 19 is made via an inwardly directed pivot pin having an innermost circular flange 22 forming a stop (illustrated in Figure 8) which is spaced slightly from the outermost surface of the connecting element 19 and is sized so as to extend across the part-circular edge part 16 of the side plate 13 as illustrated in Figure 8. The rear end of the hinge arm 12 is provided with a locking aperture 23 therethrough which is sized and positioned to receive the locking spigot 18 when the hinge is folded into its closed configuration as illustrated generally in Figure 7.

The rear part of the hinge arm 12 also carries an upwardly and rearwardly directed extension 24 which is pivotally connected via a pivot 25 to the rearmost end of the upper hinge part 11. The hinge part 11 carries an inwardly directed mounting flange 26 for securement to part of the underside of the hood or bonnet 1.

As illustrated most clearly in Figure 6, the hinge mechanism 9 also comprises an elongate support arm 27 which serves to interconnect the central part of the hinge arm 12 and the rear part of the lower hinge part 10. One end of the support arm 27 is pivotally connected via a pivot 29 to the outer side of the side plate 13 at a position spaced slightly in front of the release mechanism 17. The other end of the support arm 27 is pivotally connected, via a pivot 30 to the inner side of the hinge arm 12, at a position substantially centrally between the pivot 21 at the front edge of the hinge arm 12 and the locking aperture 23 of the rear end of the hinge arm 12.

Of course, Figure 6 illustrates the hinge mechanism 9 in a fully open configuration whereas, in normal use, with the hood or bonnet 1 of the motor vehicle being closed, the hinge mechanism 9 is closed up to adopt the configuration illustrated in Figure 7. In this configuration, the hinge arm 12 lies generally adjacent to the outer side of the side plate 13, with the support arm 27 and the connecting element 19 located generally between the hinge arm 12 and the side plate 13. As the hinge arm 12 is moved downwardly from the position illustrated in Figure 6 towards the position illustrated in Figure 7, the connecting arm 19 rotates about its pivot 20 such that the flange 22 moves forwardly so as to adopt the position illustrated in Figure 8. In this position, the outwardly-directed locking spigot 18 engages the locking aperture 23, thereby locking the hinge arm 12 in position relative to the lower hinge part 10.

When the hinge arm 12 is locked in position adjacent the lower hinge part 10 as described above, the upper hinge part 11 remains free to rotate about the extension 24 of the hinge arm 12 and hence allows the hood or bonnet 1 to be opened from its front end, so as to pivot about an axis extending transversely through the pivot 25. This allows the hood or bonnet 1 to be opened as illustrated in Figure 8, thereby providing convenient access to the engine compartment located below the hood or bonnet 1. Of course, when the hood or bonnet 1 is closed as illustrated in Figure 4, the locking mechanism at the front end of the hood or bonnet serves to retain the hood or bonnet in its normal position, and the upper hinge part 11 lies substantially adjacent the outer surface of the hinge part 12, positioned above the side plate 13 of the lower hinge part 10 as illustrated, for example, in Figures 5 and 7.

On receipt of a signal from a crash sensor, indicative of an imminent or extant collision with a pedestrian, the lifter 8 and the release mechanism 17 are actuated substantially simultaneously, or in response to one another. The locking spigot 18 is thus driven inwardly under the action of the pyrotechnic charge within the locking mechanism 17, thereby moving out of engagement with the locking aperture 23 and releasing the hinge arm 12 from the lower hinge part 10. At the same time, the lifter 8 serves to lift the rear part of the hood or bonnet 1 and hence the hinge mechanism 9 opens up towards the position illustrated in Figures 6, 10 and 11. The rear part of the hinge arm 12 moves upwardly causing the hinge arm 12 to rotate relative to the lower hinge part 10, via its pivotal connection 21 to the connecting element 19. As the hinge arm 12 moves upwardly in this manner, the support arm 27 also moves upwardly, pivoting about its pivotal connection 29 to the lower hinge part 10. However, the length of the support arm 27 is configured to restrict the degree of rotational movement of the hinge arm 12 relative to the lower hinge part 10 such that when the hinge arm 12 reaches the limit of its rotational movement, further upward movement of the rear part of the hood or bonnet 1 (and hence further upwards movement of the upper hinge part 11 secured to the hood or bonnet 1) causes the connecting element 19 to rotate rearwardly relative to the lower hinge part 10 such that the pivotal connection 21 between the connecting element 19 and the hinge arm 12, moves rearwardly following a part circular path centred on the pivot 20. As the connecting element 19 moves in this way, the flange 22 moves around the part-circular edge region 16 of the side plate 13.

Because the pivotal connection 21 between the connecting element 19 and the hinge arm 12 moves rearwardly in the manner described above whilst the rear part of the hood or bonnet 1 is driven upwardly, the entire hinge arm 12 is caused to move rearwardly relative to the lower hinge part 10 which is mounted to the motor vehicle and hence the upper hinge part 11 is also caused to move rearwardly as the hood or bonnet 1 reaches the upper limit of its movement.

This rearward movement of the upper hinge part 11 is most clearly illustrated in Figure 10 where the dashed line 31 denotes the path followed by the axis of the pivotal connection 25 between the hinge arm 12 and the upper hinge part 11. By way of illustration, the dashed line 32 illustrates the path which would be followed by the pivotal connection 25 if the pivotal connection between the forwardmost end of the hinge arm 12 and the lower hinge part 10 were fixed and not allowed to move rearwardly as described above. Path 31, when compared to path 32, clearly shows rearward movement of the upper hinge part 11 and hence rearward movement of the hood or bonnet 1 to which the upper hinge part 11 is secured. The effect of this rearward movement of the hood or bonnet 1 as its rear part is lifted, is most clearly illustrated in Figure 11, where it will be seen that the forwardmost edge 2 of the hood or bonnet 1 is allowed to move downwardly, whilst remaining clear of the front bodywork 3, in the manner as described above with reference to Figure 3.

Figure 12 illustrates an alternative configuration of hinge mechanism forming part of a safety arrangement of the present invention. In this arrangement, the hinge comprises a lower hinge part 33 secured to the main part of the motor vehicle, and an upper hinge part 34 secured to the underside of the hood or bonnet 1. A hinge arm 35 again serves to interconnect the lower hinge part 33 and the upper hinge part 34, but in this configuration, the rear end of the hinge arm 35 is pivotally connected to the rear part of the lower hinge part by a pivotal connection 36 which is fixed. The forwardmost end of the hinge arm 35 is pivotally connected to the forwardmost part of the upper hinge part 34 via a pivot 37 which is slideably received within an elongate slot 38 formed through the upper hinge part 34.

At the rear end of the upper hinge part 34, a release mechanism 39 is provided which is substantially identical to the release mechanism 17 of the above described embodiment. The release mechanism 39 incorporates a spigot configured to engage a locking aperture 40 formed through the hinge arm 35. A support arm 41 again interconnects the upper hinge part 34 and the hinge arm 35 and is pivotally connected at one end to the upper hinge part 34 and is pivotally connected at its other end to the hinge arm 35.

In the embodiment illustrated in Figure 12, a safety tether 42 in the form of a flexible cable or wire is provided which is pivotally connected at one end 43 to the forward end of the lower hinge part 33 and which is pivotally connected at its other end 44 to the support arm 41. However, it should be appreciated that the end 44 of the safety tether could instead be connected to hinge arm 35 or the upper hinge part 34.

In the normal, closed up configuration of this hinge assembly, the hinge arm 35 lies substantially adjacent the lower hinge part 33, and the pivot 37 between the hinge arm 35 and the hinge part 34 is located at the forwardmost end of the elongate slot 38, The upper hinge part 34 is normally located adjacent the hinge arm 35 and is locked with respect to the hinge arm 35 by engagement between the spigot of the release mechanism 39 and the locking aperture 40. In the closed up configuration of the hinge assembly, the flexible tether 42 has no tension applied to it and simply lies naturally under its own weight.

The hood or bonnet 1 can be opened from its front end in a generally conventional manner such that the hinge arm 35 rotates about the pivot 36 with respect to the lower hinge part 33 which is secured to the motor vehicle. However, upon actuation of the locking mechanism 39, the spigot is moved out of engagement with the locking aperture 40, so that as the rear part of the hood or bonnet 1 is driven upwardly by the lifter (not shown in Figure 12), the hinge mechanism opens as illustrated in Figure 12. As the hinge mechanism opens in this way, the upper hinge part 34 rotates with respect to the hinge arm 35 about the pivotal connection 37 until a point is reached at which the support arm 41 limits the rotational movement between the hinge part 34 and the hinge arm 35. When this point is reached, further upwards movement of the hood or bonnet 1 causes the pivot 37 to move rearwardly towards the rearmost part of the slot 38.

It will therefore be understood that the hinge mechanism illustrated in Figure 12 again causes the hood or bonnet 1 to move rearwardly as its rear part is lifted such that the rearmost edge of the hood or bonnet follows the slightly curved path illustrated at 45.

The tether 42 can be configured such that it becomes taut as the pivot 37 engages the rear end of the slot 38. However, the tether 42 can be slightly longer so that even at the fully open position of the hinge assembly illustrated in Figure 12, the tether is not taut. The purpose of the tether is to prevent the rear part of the hood or bonnet becoming detached from the motor vehicle through breakage of the various pivotal connections of the hinge assembly, in the event of a frontal impact involving the car.

The hinge assembly illustrated in Figures 2 to 11 can also be provided with a tether 42 of the type described above.

Turning now to consider Figures 13 and 14, there is illustrated a locking mechanism located beneath the forwardmost end of the hood or bonnet 1, which is configured to releasably lock the forwardmost end of the hood or bonnet relative to the chassis or main part of the motor vehicle. The locking mechanism comprises a mounting plate 50 which is secured to the underside of the hood or bonnet 1. An elongate locking pin 51 depends downwardly from the mounting plate 50 and has an enlarged head 52 at its lowermost end.

A bearing washer 53 having a peripheral inwardly turned rim 54 is provided around the locking pin 51, and a helical spring 55 is provided around the locking pin 51 so as to act between the mounting plate 50 and the bearing washer 53, to biase the bearing washer 53 away from the mounting plate 50.

The enlarged head 52 is configured to be received through an elongate locking slot 56 formed through a locking plate 57 which is mounted to the vehicle chassis. As illustrated most clearly in Figure 14, a locking finger 58 is pivotally connected to the underside of the locking plate 57 via a pivot 59 at one end. The other end of the locking finger 58 is connected to the end of an actuating cable 60 which runs through a guide 61 depending downwardly from the undersurface ofthe plate 57. A spring 62 is provided around the end region of the actuating cable and acts between the locking finger 58 and the guide 60 to bias the end of the locking finger remote from the pivot 59 towards the locking slot 56.

Figure 13 illustrates the locking mechanism in a locked configuration, in which the locking head 52 of the pin 50 has been inserted through the slot 56 formed in the plate 57. As the pin is lowered towards this position, the tapered end surface of the locking head 52 bears against the biased finger 58, thereby rotating the finger 58 about its pivot 59, to move the finger in a clockwise direction as illustrated in Figure 14. As the locking head 52 passes the locking finger 58, the locking finger 58 is urged, under the action of the spring 62, back towards its position illustrated in Figure 14 in which it extends partially across the locking slot 56, thereby retaining the locking head 52 therebelow. It will be understood that the locking mechanism can be released by pulling the actuating cable 60 in the direction illustrated by arrow 63, and serves to rotate the locking finger 58 away from the locking slot 56 to allow the locking head 52 to move there past.

Figure 15 illustrates the configuration of the locking mechanism after the lifting arrangement provided at the rear end of the bonnet has been actuated to lift the rear part of the bonnet. It will be seen that the front edge 2 of the bonnet has been moved rearwardly and downwardly. Rearwards movement of the front end of the bonnet is permitted by virtue of the sliding engagement of the shaft of the locking pin 52 within the locking slot 56. It will be seen from Figure 14, that at any longitudinal position of the pin 51 along the slot 56, the locking head 52 of the pin is always retained by the locking finger 58.

Downwards movement of the front end of the bonnet 1 causes the locking pin 51 to be driven slightly further through the locking slot 56 which serves to compress the spring 55 acting between the bearing washer 53 and the mounting plate 50.

Figures 16 to 18 illustrate an alternative, but largely similar, type of locking mechanism provided beneath the front part of the hood or bonnet 1. In this arrangement, the locking pin 51 is mounted to the mounting plate 50 so as to allow for a degree of deflection of the pin 51 relative to the mounting plate 50, and hence also relative to the hood or bonnet 1 to which the mounting plate 50 is secured. Also, in this arrangement, the elongate locking slot 56 of the above-mentioned arrangement is replaced with a locking aperture 64 which is sized so as to receive the locking head 52 of the pin 51 therethrough, but to prevent substantial movement of the locking pin 51 relative to the plate 57. In this arrangement, as the forwardmost edge 2 of the hood or bonnet 1 moves downwardly in response to upwards movement of the rear part of the hood or bonnet 1, the locking head 52 of the locking pin 51 remains substantially stationary relative to the plate 57. However, the locking pin is caused to deflect relative to the mounting plate 50 and hence also to deflect relative to the hood or bonnet 1.

It should therefore be appreciated that both of the above-mentioned locking mechanisms provided underneath the front end of the hood or bonnet 1 permit downwards and rearwards movement of the forwardmost edge 2 of the hood or bonnet 1 whilst still ensuring a secure connection between the hood or bonnet 1 and the chassis of the motor vehicle.

In the present specification "comprises" means "includes or consists of and "comprising" means "including or consisting of.

Claims

1. A safety arrangement to lift the rear part of the hood or bonnet of a motor vehicle, the safety arrangement comprising a hinge connecting the rear part of the hood or bonnet to the main part of the vehicle to permit the front part of the hood or bonnet to be opened, the hinge having: a first hinge part and a second hinge part, one of said hinge parts being secured to or formed integrally with the main part of the vehicle and the other hinge part being secured to or formed integrally with the rear part of the hood or bonnet; a hinge arm pivotally connected at one end to said first hinge part and connected at its other end to said second hinge part, said connection between said other end of the hinge arm and said second hinge part comprising a moveable pivot to allow rotational movement of the hinge arm relative to said second hinge part, said moveable pivot being moveable with respect to said second hinge part between a first position and a second position, the second position being spaced rearwardly of the first position; said hinge arm being releasably connected to said second hinge part such that said pivot is located in said first position, and there being provided a release mechanism to release said releasable connection to allow the rear part of the hood or bonnet to be lifted, wherein said moveable pivot moves from said first position towards said second position as the rear part of the hood or bonnet is lifted.

2. A safety arrangement according to claim 1, wherein said other end of the hinge arm is connected to said second hinge part via a connecting element located between the hinge arm and second hinge part, said connecting element being pivotally connected to said other end of the hinge arm by said moveable pivot and pivotally connected to said second hinge part by a second pivot, such that the connecting element pivots about said second pivot during lifting of the rear part of the hood or bonnet, thereby moving the moveable pivot rearwardly.

3. A safety arrangement according to claim 2, wherein said second hinge part is secured to or formed integrally with the main part of the motor vehicle.

4. A safety arrangement according to claim 1, wherein said moveable pivot is slideably received within an elongate slot formed on said second hinge part.

5. A safety arrangement according to claim 4, wherein said second hinge part is secured to or formed integrally with the rear part of the hood or bonnet.

6. A safety arrangement according to any preceding claim comprising a tether connected at one end to one of said hinge parts, and connected at its other end to the other hinge part or to the hinge arm.

7. A safety arrangement according to any preceding claim further comprising an elongate support arm, one end of the support arm being pivotally connected to said hinge arm at a position between its two ends, and the other end of the support arm being pivotally connected to said second hinge part at a position spaced rearwardly of said moveable pivot.

8. A safety arrangement according to claim 7, wherein said support arm has a length effective to limit the degree of rotational movement between said hinge arm and said second hinge part during lifting of the rear part of the hood or bonnet.

9. A safety arrangement according to claim 7 or 8 as dependent upon any one of claims 1 to 5, comprising a tether connected at one end to one of said hinge parts and connected at its other end to said support arm.

10. A safety arrangement according to any preceding claim, wherein said release mechanism is actuable by a pyrotechnic charge.

11. A safety arrangement according to any preceding claim, wherein said release mechanism comprises a moveable locking pin carried by said second hinge part, the locking pin being received within a locking aperture provided on the hinge arm.

12. A safety arrangement according to any preceding claim further comprising a lifting element located beneath the rear part of the hood or bonnet and actuable to lift the rear part of the hood or bonnet.

13. A safety arrangement according to claim 12, wherein said release mechanism is actuable in response to actuation of said lifting element.

14. A safety aπangement according to claim 12, wherein said lifting element is actuable in response to actuation of said release mechanism.

15. A safety arrangement according to any preceding claim further comprising a locking arrangement to releasably lock the front part of the hood or bonnet in a closed position, the locking arrangement comprising a locking element carried by the front part of the hood or bonnet, and a locking mechanism provided on the main part of the vehicle to releasably engage said locking element, whilst allowing downwards movement of the locking element relative to the main part of the vehicle.

16. A safety arrangement according to claim 15, wherein said locking mechanism is configured to releasably engage said locking element whilst allowing sliding movement of said locking element relative to said mechanism.

17. A safety arrangement according to claim 16, wherein said locking mechanism comprises a plate having a slot formed therein, said locking element being releasably retained within said slot for sliding movement therein.

18. A safety arrangement according to claim 15, wherein said locking element is mounted to the front part of said hood or bonnet for deflection relative to said hood or bonnet.