The invention relates to a safety device for a vehicle door handle, in particular in order to avoid unsolicited opening of said door during a side crash scenario.

When a vehicle undergoes a lateral collision, the inertia of the handle pieces can lead to an actuation of the door latch. Major risk in that case is the opening of the door, meaning that the occupants are directly exposed to the outside, while free objects can be thrown out of the vehicle.

It is known to use movement prevention devices, actuated by the important accelerations often of several tens of g that lock the handle to avoid opening of the vehicle door. Most commonly, said movement prevention devices use an inertia! mass which is moved by the change in inertia so as to enter a blocking position. In said blocking position, mechanical means engage with the latch or handle mechanics in a way that prevents opening of the door.

The known movement prevention devices can be divided in two main categories : temporary blocking and permanent blocking. The temporary blocking devices use returning means such as a spring to bring back the inertial mass in a non- blocking position as soon as the acceleration diminishes beyond a reasonable value. The permanent blocking devices have no means to bring back the inertial mass in the non- blocking position, and often comprise in addition means to keep the mechanical means engaged with the latch or handle mechanics even after the crash subsequent accelerations arc gone.

The temporary blocking devices ensure that the occupants of the vehicle can open the door once the vehicle has stabilized itself, or that rescuers can open said door to pull them out. The problem with said temporary blocking devices is that vibrations and the inertia changes due to rebounds of the vehicle or to secondary impacts are likely to free the mechanical means of the movement blocking dev ice from the handle mechanism. Permanent blocking device are more effective in keeping the door closed during the crash, but the latches or handles remain blocked in locked state even when the doors could be opened safely again.

Damped inert ial systems use a temporary blocking architecture, in which a rotational damper selectively delays the return to the non-blocking position of the movement prevention device. Movement prevention devices using damped inertial systems combine the advantages of both permanent and temporary blocking devices. During the crash the movement prevention device is maintained in blocking position during the risk time interval, and returns to non-blocking position afterward, allowing easy evacuation of the vehicle.

The known damped inertial systems are, however, space consuming, as the damping means often comprise a gear transmission mechanism or a piston that absorbs the kinetic energy during the return to non-blocking position. In order to overcome at least partially the aforementioned drawbacks, the invention has for object a vehicle door handle movement prevention device, comprising

- a damped inertial system, mobile in rotation around a rotation axis between a locking position domain in which mechanical means of said damped inertial system interfere with an opening mechanism to prevent actuating the door handle, and a rest position domain in which the door handle can be freely actuated,

- elastic means configured to bring the damped inertial system back to its rest position domain in absence of acceleration,

characterized in that the damped inertial system comprises :

- a cylindrical body hinged on the rotation axis,

- an arm fixed to the cylindrical body, and extending radially from the rotation axis,

- an inertial mass supported at the free end of said arm, configured to bring the inertial system in locking position when inertial forces due to accelerations caused by a side crash of the vehicle are applied on said inertial mass, and in that the damped inertial system, further comprises a rotational damper integrated in the cylindrical body around rotation axis, the rotational damper being configured to temporize the return of the inertial system from the locking position domain to the rest position domain.

This vehicle door handle movement prevention device forms a compact and easily handled device. This device can be implemented in a great number of vehicle doors as it does not depend on the door handle characteristics such as weight and element lengths.

The device can also have one or more of the following characteristics, taken separately or in combination.

The rotational damper is configured to slow the rotation of the inertial system in the rotational direction from the locking position domain to the rest position domain.

It further comprises a shaft fixed to the handle and forming the rotational axis, the rotational damper surrounding said shaft so as to transmit damped reaction forces from the shaft to the inertial system.

The rotational damper is a rotational oil damper.

The mechanical means comprise a pin, cooperating with a shoulder of a door opening mechanism lever to prevent at least partially motion of said door opening mechanism lever when the damped inertial system is in its locking position domain, the shoulder being configured to push the damped inertial system in an extremal locking position on actuation of the door handle while the damped inertial system is in its locking position domain.

The elastic means comprise a coil spring, the coil spring surrounding the rotation axis.

The coil spring surrounds a portion of the rotational damper.

The coil spring is surrounded in the cylindrical body.

The elastic means comprise a coil spring, the coil spring being attached to the arm. The inertial mass comprises a socket in order to receive a pin for adjusting the weight of said inertial mass.

The locking position domain and the rest position domain are angular apertures of respectively about 1 2° and 10°,

The damper is configured to bring the inertial system from the locking position domain to the rest position domain in between 0,5 and 1 ,5 seconds.

Another object of the invention is the associated vehicle door handle comprising - an opening mechanism configured to allow opening of the door when actuated,

- a lever configured to actuate the opening mechanism when set in motion, characterized in that is comprises a vehicle door handle movement prevention device, comprising :

- a damped inertial system, mobile in rotation around a rotation axis between a locking position domain in which mechanical means of said damped inertial system interfere with the opening mechanism to prevent actuating the door handle, and a rest position domain in which the door handle can be freely actuated,

- elastic means configured to bring the damped inertial system back to its rest position domain in absence of acceleration,

the damped inertial system comprising :

- a cylindrical body hinged on the rotation axis,

- an arm fixed to the cylindrical body, and extending radially from the rotation axis,

- an inertial mass supported at the free end of said arm, configured to bring the inertial system in locking position when inertial forces due to accelerations caused by a side crash of the vehicle are applied on said inertial mass, and the damped inertial system further comprising a rotational damper integrated in the cylindrical body around rotation axis, the rotational damper being configured to temporize the return of the inertia! system from the locking position domain to the rest position domain.

Other characteristics and advantages will appear at the reading of the following description of the surrounded figures, among which :

- Figure 1 is an exploded view of a door handle comprising a system according to the invention,

- Figure 2 is a perspective view of one embodiment of the inertial system,

- Figure 3 is a perspective view of the movement prevention device using the inertial system of figure 2 shown in a different angle,

- Figures 4 and 5 show different embodiments of the inertial system according to the invention,

- Figure 6 is a schematic view of the inertial system working with some of the door handle elements,

- Figure 7 is a diagram illustrating the position of the inertial system over time in a side crash scenario.

On all figures, the same references relate to the same elements. Figure 1 depicts the different elements of a vehicle door handle 1 comprising a movement prevention device 3 according to the invention.

The handle 1 comprises a lever 5, mounted mobile in a bracket 7. The lever 5 is placed on the outside of the vehicle door, and is actuated by the user to open the handle 1 , for example by rotation of the lever 5 around an articulation in a lever swan neck 51 ,

The handle 1 comprises an opening mechanism 9, said opening mechanism 9 comprises in this embodiment a main lever 1 1 , a lever spring 13, here a coil spring, a bowden cable 15 and the movement prevention device 3.

The opening mechanism 9 i incorporated in the bracket 7. When the user actuates the lever 5, a lever column 3 placed on the side of the lever 5 opposite to the lever swan neck 5 1 sets the main lever 1 1 in motion. The main lever 1 1 in turn actuates the bowden cable 1 5, The bowden cable 15 then transmits the actuation to the latch located in the door. The lever spring 1 3 ensures that the main lever 1 1 returns in initial position afterward.

The movement prevention device 3 comprises a damped inertial system 17, an inertial system shaft 19, and an inertial system spring 21 . The shaft 19 is solidly fixed to the bracket 7, and is also fixed to a rotational damper, not represented, inside the damped inertial system 17.

The damped inertial system is shown in a more detailed fashion in figure 2.

The damped inertial system 17 comprises a cylindrical body 23, an arm 25 extending radially from said cylindrical body 23, and an integrated inertial mass 27 at further end of the arm 25, and a pin 29, also extending radially from the cylindrical body 23, not seen on figure 2 as it is on the other side of the cylindrical body 23.

The integrated inertial mass 27 at the end of arm 25 comprises a socket 31 . It is foreseen to insert in said socket 31 an additional weight not represented, to increase and/or tune the inertial mass total weight in adequacy with the required engagement time of the movement prevention device 3. Adapting the inertial mass weight value allows to implement a unique embodiment of the inertial system 17 in even more handles, while changing just a weight pin inserted in socket 31 . As seen on figure 2, the inertial spring 21 is in the preferred embodiment integrated in the cylindrical body 23 under a cover 33 so that only an end 35 of the spring 21 is visible. The spring 21 surrounds the rotational damper 37. On figure 2, the rotational damper 37 is tubular, and in contact with the shaft 19 when mounted. The rotational damper 37 is placed between the shaft 19 not shown on figure 2 and the rotational damper cylindrical body 23. The rotational damper transmits reaction forces from the shaft 19 to the inertial system 1 7, via a damping mechanism such as an oil damping mechanism, where oil circulating between chambers dissipates the kinetic energy . This allows to temporize the return from locking positions of the inertial system 17 to not locking or rest positions. On figure 3, the shaft 19 is shown in its final place, at the center of the cylindrical body, along a central rotation axis A of the cylindrical body 23. The pin 29 is also not visible on figure 2, as it is placed on the other side of the cylindrical cylindrical body 23. On figure 3 is represented the complete movement prevention device 3. As can be seen, this device 3 is compact and implemented simply by attaching the shaft 19 ends to the bracket 7 of handle 1.

The shaft 1 cooperates with the bracket 7 to maintain the inertial system 17 in place around rotation axis A .

The figures 4 and 5 represent different embodiments of the inertial system 17, different from each other in the position of the inertial system spring 21 .

In figure 4, the spring 21 surrounds a protruding part of the rotational damper 37, and is thus not part of the cylindrical body 23. Alternatively, the spring 21 can only surround the shaft 1 . Also, on figure 4 the pin 29 can be seen.

In figure 5, the spring 21 is attached to the arm 25. In this embodiment, the spring 21 works in axial compression, as opposed to previous embodiments where said spring 21 works in radial compression.

Other embodiments using other elastic means are also to be considered, Figures 6 and 7 illustrate the operating of the inertial system as described.

In figure 6 are schematically depicted the inertial system 17 viewed along rotation axis A, the lever 5 and the main lever 1 1. The inertial system is shown in three different angular positions. The three angular positions define two position domains in form of angular apertures a and β.

The two extremal positions correspond to the rest or default position R and the maximum engagement or locking position L. The rest position R is the position assumed in absence of inertial displacement. The locking position L is assumed when forces due to side acceleration overcome the resistance of the inertia! system spring 21.

While the inertial system 17 is within the angular aperture β, the main lever 1 1 can freely be actuated in order to open the vehicle door. While the inertial system 17 is within the angular aperture a, the pin 29 is on the path of a shoulder 39 of the main lever 1 1. Thus, if the inertiai system is within the angular aperture a, whenever an actuation of the door lever 5 takes place, the shoulder 39 is brought in contact with the pin 29, the force applied on door lever 5 bringing the inertiai system via the pin 29 to shoulder 39 contact in the extremal locking position L, where said inertiai system 17 5 blocks the movement of main lever 11 , and thus opening of the door handle 1.

In the chosen embodiment, the value for a is about 10°, and about 12° for β. The position represented on figure 6 marking the transition from a to β is called the intermediary position /.

Once the actuating forces on door lever 5 have decreased, the rotational damper

10 37 in cylindrical body 23 delays the return of inertiai system 17 to rest position R. Said delaying maintains the inertiai system 17 for a certain amount of time within the angular aperture a. By tuning the rotational damper mechanism 37 in comparison to the inertiai system spring 21 , it is possible to maintain the inertiai system during any predetermined amount of time in angular aperture a. By choosing said predetermined amount of time

15 between 0.5 and 1 second, the risk of door opening due to a rebound or vibration effect is avoided, while the door can still be opened once the vehicle has stabilized.

In figure 7 is depicted the rotation angle of the inertiai system as a function of time, in a side crash scenario. The rotation angle is measured with reference to the rest position R. So 0° designates said rest position R, from 0° to 12° the inertiai system 17 is 0 in angular aperture β and from 12° to 22° the inertiai system 1 7 is in angular aperture a.

22° corresponds to the locking position L.

At instant t = 0, the crash occurs. Immediately, the inertiai system is brought in extremal locking position L, 0.5 seconds later, the acceleration decreases, the inertiai system is brought back to rest position R by the inertiai system spring 21 : the rotation

25 angle decreases, at a certain speed determined by the rotational damper 37. One second later at t = 1.5s, the inertia! system 17 reaches intermediary position /, the door lever is free again. The inertiai system 17 then slowly returns to rest position R. The preferred value for the return to rest position is 1.5 seconds, but values between 1 and 5 seconds are also convenient.

30 During the first 1.5 seconds, the door is consequently blocked, and free afterward, meaning that during the short time interval after the crash where a rebound or oscillation effect is likely to result in opening the door, the movement prevention device 3 prevents opening the door. Immediately after said time interval the door is free again, and the vehicle can be evacuated or the occupants can be tended. The invention allows to produce a simple and compact movement prevention device 3 using a damped inertia! system 17 by integrating the rotational damper 37 in the inertia! system cylindrical body 23. As a result, the obtained device 3 is easily implementable in various door handle configurations.