WO2013111167A1

WO2013111167A1 - A safety device for a vehicle seat. a frame for said seat and a vehicle comprising said device.

Info

Publication number: WO2013111167A1
Application number: PCT/IT2012/000025
Authority: WO
Inventors: Nicola Ruggiero
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-01-27
Filing date: 2012-01-27
Publication date: 2013-08-01
Anticipated expiration: 2014-07-27

Description

A SAFETY DEVICE FOR A VEHICLE SEAT. A FRAME FOR SAID SEAT

AND A VEHICLE COMPRISING SAID DEVICE,

Description Field of the art

The present invention relates to a safety device for a vehicle seat, a frame for said seat and a vehicle comprising said device.

More precisely, the present invention relates to a passive safety device for absorbing and dissipating the energy generated during a collision with another vehicle or with an obstacle, in particular such as to prevent the effect known as whiplash.

Large investments have been made by motor vehicle manufacturers to improve the safety of the passengers in a case of an accident, and to reduce the biological damage caused by an impact.

A vehicle in movement has a certain quantity of motion which increases as the velocity increases, being given by the product of the weight by the velocity.

Immediately after the impact the quantity of motion becomes zero. The variation of the quantity of motion is given by the product between the force of impact and the time during which impact occurs. Thus the longer the time interval in which the impact occurs, the smaller the force of the impact.

Based on this concept, motor vehicle construction companies have become more aware of the passive safety of the passenger, and have developed various technologies for reducing the danger of road accidents to a minimum, by increasing the deformation of the structures.

This has led, for example, to the use of seat safety belts, or airbags, which more slowly reduce the quantity of motion of the passengers on board the vehicle, or deformable car bodies, which cause the quantity of motion of the motor vehicle, and consequently of the passenger, to be reduced more slowly.

Despite the above, the death rate in road accidents is still high.

Further, in the case of small-entity accidents, the greatest damage to the person, with painful results and long-lasting repercussions that often become chronic, are caused by what is known as the whiplash effect. Insurance companies today pay out considerable sums of money for injuries resulting from persons suffering from this effect.

Description of the Prior Art.

At present there are no vehicles provided with safety devices on the market which can dampen the effect and reduce the damage to the human body caused by whiplash.

However in the art it is known the patent document US3917339, which describes an absorbing system for dampening and softening the effect of a collision on a row of seats in a vehicle, in particular a bus.

The system in question comprises a plurality of seats in a column and mounted on a common guide such as to slide longitudinally with respect to the vehicle frame.

In a rear zone of the cabin, a container is arranged that is provided with springs operatively associated to the above-cited guide, such as to deform elastically and soften the blow received from the collision, thus enabling a gradual displacement of the seats with respect to the frame.

To prevent an unexpected elastic return, which would be still more damaging than the collision, the system is provided with a pair of pneumatic or hydraulic shock absorbers acting in collaboration with the springs in order to make return into position more gradual.

The system of document US3917339 is disadvantageous^ complicated and bulky.

The box-shaped structure cannot, in fact, be used in the motor car field, where the spaces available are much smaller.

Among other things, the presence of pneumatic or hydraulic shock absorbers makes the structure of the system complicated, as seal elements, breather pipes, etc. are required.

To confirm this, it can be seen how the system in question, though not entirely recent, has not been applied or been subject to any further evolution in the field of road vehicle safety.

Summary of the Invention

The technical aim of the present invention is to provide a safety device for a seat of a vehicle, a frame for said seat and a vehicle comprising said device, which are free of the drawbacks encountered in the prior art. In the field of the technical task, an aim of the present invention is to realise a safety device for a vehicle seat that is high-performance and simple to install. Further, an aim of the present invention is to realise a safety device for a vehicle seat that is particularly economical and of contained dimensions.

A further aim of the present invention is to made available a frame for a vehicle seat and a vehicle having high safety standards.

These and other aims of the present invention that will be more fully clarified during the following description are attained by a safety device for a vehicle seat, a frame for said seat and a vehicle comprising said device according to one or more of the appended claims.

Brief description of the drawings.

A preferred but not exclusive embodiment will now be described by way of non- limiting example of a safety device for a vehicle seat, a frame for said seat and a vehicle comprising said device, as illustrated in the accompanying figures, in which:

- figure 1 is a perspective view of a safety device for a vehicle seat according to a first variant of the present invention;

- figure 2 is a partially-exploded view of the device of figure 1 ;

- figure 3 is a perspective view of a vehicle seat provided with a plurality of devices of figure 1 ;

- figure 4 is a schematic lateral view of a vehicle provided with a plurality of the seats of figure 3;

- figures 5 and 6 are perspective views, from two different angles, of a vehicle seat, according to a second variant of the present invention, respectively before and after a crash;

- figures 7 and 8 are perspective views from two different angles of a detail of the vehicle seat of figure 5 and 6, before a crash;

- figures 9 and 10 are perspective views from two different angles of a detail of a seat as in figures 5 and 6, after a crash;

- figures 11 and 12 illustrate a variant of a detail of the vehicle seat of figures 5 and 6, respectively before a collision and after a collision;

- figures 13 and 14 are two views of an enlarged detail of the element illustrated in figures 11 and 12;

- figure 15 is a motor vehicle on which the seats of the present invention are mounted;

- figure 16 is a schematic illustration of a block diagram of an embodiment of a fluid-dynamic loading device which can be used in the vehicle seat of figures 5 and 6.

Description of the preferred embodiments of the invention.

With reference to the accompanying figures, numeral 1 indicates a safety (or anti- whiplash) device for a seat 100 of a vehicle 200 according to the present invention.

More precisely, the safety device 1 is an energy-absorbing and dissipating device.

This device 1 is configured such to be installed to a seat 100 of a vehicle 200 (in particular a motor vehicle), preferably at each of its seats 100.

As known, the vehicles are provided with a support framework 201, to which the various components of the vehicle are constrained, be they elements of bodywork, mechanical elements or upholstery.

In particular, the framework 201 includes a platform 202 to which the seats 100 (more fully described herein below) are connected.

According to a first variant of the invention, the seats 100 are fitted with the safety device 1, which is operatively interposed between the seat 100 and the platform 202.

More precisely, the safety device 1 comprises a guide element 2, a slider 3 slidingly associated to the guide element 2, and a damping body 4 operatively interposed between the slider 3 itself and aii end stop 6 of the guide element 2, in order to oppose a displacement of the slider 3 along the guide element 2 itself in order to reduce the speed (thus dissipating the kinetic energy).

In this way, a yielding coupling is defined between the seat 100 itself and the framework 201 of the vehicle 200, which has the effect of slowing down the change in momentum of the seat-passenger/driver group and thus lengthening the duration of the deceleration.

This yielding constraint advantageously enables absorption of the stresses (impulsive) withstood by the frame 200 itself following a collision, without completely unloading the said stresses onto the seat 100 (and therefore on the driver or passenger). In fact, during a collision between the vehicle 200 and a body (be it a fixed obstacle or another vehicle) the impulsive impact force applied to the framework 201 unloads onto the seats 100 and on all the bodies within the cabin.

The driver or passenger, being unconstrained to the seat 100 (in particular as regards the head), will tend by inertia to continue her or his motion prior to the impact, thus undergoing a strong backlash, the so-called whiplash injuries.

The presence of the safety device 1 interposed between the frame 1 and the seat 100 allows this whiplash to be avoided, as the energy of the impact is dissipated in the damping body 4.

Preferably, each seat 100 comprises a pair of devices 1 for the absorption and dissipation of energy. Even more preferably, such devices 1 are mounted symmetrically with respect to a centre-line of the seat 100 (in particular of the seating part thereof) in order to best distribute the loads.

Structurally, the guide element 2 extends along a main axis thereof such as to define an operative direction "A" of the device 1.

The guide element 2 is further provided with rigid connection means 5 for connecting with the platform 202 of the vehicle 200 (for example by means of screws, rivets or the like).

More preferably, the guide element 2 (and therefore the device 1) is attached to the platform 202 of the vehicle 200 such as to be oriented parallel to the travelling direction "D" of the vehicle 200 itself. In other words, the operative direction "A" corresponds to the travelling direction of the vehicle 200.

In this way, the safety device 1 is effective for frontal accidents or crashes.

However, by orientating the device 1 at right angles to the travelling direction of the vehicle 200, it might have an equal effect even during lateral collisions.

Note that the device 1 further comprises an end stop 6 rigidly connected to a second end portion of the guide element 2.

The slider 3 is slidably associated to the guide element 2 such as to slide relatively thereto along said operative direction "A", towards and away from the end stop 6. Similarly to the guide element 2, the slider 3 is provided with rigid connection means 7 with the seat 100 (such as screws, rivets or the like).

According to the invention, the dampingbody 4 is operatively interposed between the slider 3 and the end stop 6, along the operative direction "A", so as to oppose a displacement of the slider 3 itself along the guide element 2. This damping body 4 has a ductile structure, being configured such as to deform plastically following a displacement of the slider 3 along the guide element 2, i.e. by opposing this displacement the speed thereof is reduced.

In use, displacement of the slider 3 to which reference is made is linked to the inertial mass associated with it (seat and passenger/driver) and the acceleration imparted to the vehicle 200 by the collision.

In other words, the end stop 6 (and with it the guide element 2) moves in the direction of the impact force, while the slider 3 tends to move in the reverse direction with respect thereto due to the inertia of the body associated thereto. The interposing of the damping body 4 thus absorbs the kinetic energy of the impact, making its effect on the seat 100 less full-on, and consequently also the effect on the passenger/driver (and in the best scenario cancelling it completely). In the present discussion, the term flexible refers to a structure (defined by the type of material, the geometry and internal tensions) capable of absorbing impacts by plastically deforming, or dissipating the kinetic energy of impact with an elastic return of minimum entity (ideally negligible).

In particular, the damping body 4 is a wire-shaped metal spring, provided with coils that are far apart, and preloaded to a predefined force, which at the moment of crushing opposes a force contrary to the pressure received by crushing in on itself. This is activated at both low and high speeds. In the following the components of the device 1 according to the present invention will be discussed in more detail.

In the illustrated embodiment, the guide^" element body which extends along a main axis thereof (corresponding to the operative direction "A") between two opposite ends 2a.

This longitudinal body is channel-shaped, i.e. it exhibits a central groove 2b oriented along its main axis.

Preferably, the longitudinal body is a profiled element made by extrusion.

The slider 3 is slidably inserted within this groove 2b.

The end stop 6 is preferably inserted in the groove 2b at an end 2a thereof. ,

In the illustrated embodiment, the end stop 6 is defined by a wall 6a, fixed solidly to the channel (preferably by welding) and transversal (perpendicular) to the operative direction "A".

Furthermore, the guide body 2 preferably has two lateral wings 2c the function of which will be better explained in the following. The slider 3, as mentioned, is slidingly associated to the guide element 2 such as to be able to slide relatively thereto along the predetermined operative direction "A".

More precisely, the slider 3 is movable along the operative direction "A" between a first position, i.e. an operating position, and a second position, i.e. an emergency position.

In the first position (operating position) the slider 3, being rigidly connected to the seat 100, maintains it in the classic driving position.

In other words, during normal use of the vehicle 200, the slider 3 has no relative motion with respect to the guide element 2, and keeps it in place.

In contrast, during a collision, the slider 3 slides along the guide member 2 (in the operative direction "A") in an opposite direction to the direction imparted to the vehicle 200 by the collision, thus deforming the damping body 4 and reducing the effect that this collision unloads onto the seat 100.

The slider 3 is preferably at least partly defined by a block 3a (or carriage) slidingly associated to the guide element 2 (preferably slidably inserted into the groove 2b).

The block 3 a is preferably inserted substantially snugly in the groove 2b, so as to slide internally thereof in a straight line, without oscillating motions (such as a yawing motion, for example).

The slider 3 thus exhibits an active face 3 b facing the wall 6a (or end stop 6) between which the damping body 4 is interposed.

The damping body 4 is therefore interposed between the active face 3b of the slider 3 and the wall 6a of the end stop 6, in contact with both.

Note that the damping body 4 is of the single-use disposable type, i.e. once deformed as a result of a collision of the vehicle 200 it is replaced.

In fact, being plastically deformable, once the safety device 1 has entered into action, the damping body 4 does not return into its original configuration, as it is no longer usable.

In the light of this, the damping body 4 is positioned internally of the groove 2b so that it is easy to remove, thus facilitating the work of the operator repairing the vehicle 200 following the impact.

Moreover, the presence of a single-use deformable body makes the device 1 particularly simple and economic to realise.

Also, in this way the most critical component of the device 1 is replaced and mounted ex-novo for each activation (and therefore at each collision), preventing it from being damaged during collisions, which would compromise the reliability of the device 1.

The security device 1 therefore has substantially two (only) configurations; a passive configuration, in which the damping body 4 is undeformed, and an active configuration in which the damping body 4 is plastically deformed to reduce the relative velocity between the slider 3 and the end stop 6.

In order to ensure activation of the device only in case of collision of the vehicle 200 (either bumping or frontal or lateral impact collision, depending on the operative direction "A" of the device 1), the device 1 is configured to switch from the passive configuration to the active configuration only in response to (or following) an impulsive thrust action parallel to the operative direction "A" exerted on the slider 3 and having intensity that is higher than a predetermined threshold value.

In other words, the damping body 4 has a sufficiently high yield strength to avoid deformation up to the exceeding of this value (the threshold value). The yield strength of the damping body 4 is preferably between 700 N and 5000 N, that is, it can absorb a crash velocity of from 5 Km/h to 35 Km/h (but is not limiting; these are the speeds imposed by Euro Neap standard tests).

Further, the damping body 4 is sufficiently resistant not to be subject to large deformations up to load values close to the above mentioned threshold value. Even more preferably, the state of deformation of the damping body 4 is proportional to the intensity of impulsive thrust.

In other words, the damping capacity (dissipation) of the damping body 4 increases as the displacement of the slider 3 along the guide element 2 increases.

Preferably, the above-mentioned threshold value is between 50 kg-force (490.5 N) and 100 kg-force (981 N), more preferably in the environs of 70 kg-force (686.7 N).

In this way the activation of the device 1 is advantageously ensured only in a case of collision.

The damping body 4 is preferably spring-shaped, i.e. defined by a metal wire 4a twisted substantially into a helical shape, thus defining a succession of turns. Contrary to the elastic springs, the damping body 4 is substantially inelastic.

In fact, given a same coil diameter as the coils (or rings) of a (compression) elastic spring, the distance between two successive turns of damping body 4 is considerably greater.

In other words, for a same given diameter, the pitch of the turns of the damping body 4 is greater (greater or double) than that of the turns of an elastic compression spring.

5 Note that in the illustrated embodiment, the damping body 4 is configured to work in compression.

Consequently, such a damping body 4 is configured to deform plastically following a displacement of the slider 3 along the guide element 2 in approaching the end stop 6.

i o Alternatively, however, a damping body can be used which is configured to work in traction, and hence to plastically deform as a result of a displacement of the slider 3 along the guide element 2 away from the end stop 6.

Preferably, the lengthening of the pitch is obtained by a process of yielding of the material, thus losing the elastic capacity thereof.

15 It is therefore possible to define the damping body 4 as an inelastic non-returning spring.

Preferably, the damping body 4 is inserted into the groove 2b of the guide element

2 substantially snugly, such as not to flex during the deformation.

For safety reasons, the device 1 preferably comprises an activating system 8

20 associated to the slider 3 and/or the damping body 4 such as to enable movement and/or deformation only when the predetermined threshold value is exceeded in terms of the intensity of the action of the impulsive thrust. In the preferred embodiment (for safety reasons) the activation system 8 comprises at least a blocking member 8a associated to the slider 3 and movable between a 5 blocking position, in which it prevents the movement of the slider 3 along the guide element 2, and a release position in which it does not interfere with the slider 3. This blocking member 8a is configured to pass from the blocked position to the release position as a result of exceeding the threshold value of the action of impulsive thrust.

0 In a first embodiment, this blocking member 8 is of a mechanical type.

In this embodiment (illustrated), the blocking member 8a is in fact associated with elastic means 9 that are transversally movable to the operative direction "A" in order for it to be maintained the blocked position.

The elastic means 9 are in fact configured to act thrustingly on the blocking 5 member 8a transversally to the operative direction "A" so as to position the blocking member 8 in an incidental position in relation to the slider 3, preventing movement thereof along that direction.

The blocking member 8a acts substantially as a pawl stop.

In the preferred embodiment, the blocking member 8a, in the blocked position, projects into the groove 2b (preferably crossing a lateral wall thereof).

The blocking member 8 a preferably has a rounded shape such as to transmit at least a part of the action of thrust of the slider 3 in the operative direction "A" to the elastic means 9.

In other words, the rounded geometry of the blocking member 8a means that a part of the thrust that the slider 3 exerts on the blocking member 8a along the operative direction "A" is translated transversally (preferably perpendicular) thereto.

In the illustrated embodiment, the blocking member 8a exhibits a semi-spherical portion that projects internally of the groove 2b when it is in the blocked position. In an alternative embodiment (or in addition to the blocking member 8a), the activating system is of a controlled type and is provided with an impact detection sensor, a control unit and an actuator capable of moving the blocking member from the blocked to the release positions.

Note that the sensor can be a true and proper impact sensor, or a velocity or acceleration sensor, configured such as to detect sudden changes in motion of the vehicle (which if too sharp can only result from a collision).

The device 1 preferably comprises an auxiliary damper 10 associated to the slider 3 and configured such as to cooperate with the damping body 4 along the operative direction "A".

In the illustrated embodiment, the auxiliary damper 10 is of the friction type.

Alternatively, however, the auxiliary damper 10 could also be of other types (mechanical, etc. ..).

Note that the auxiliary damper 10 is operatively connected in series with the damping body 4. Therefore its dissipating action is added to the dissipating action of the damping body 4.

In the illustrated embodiment, the auxiliary damper 10 comprises a block 10a inserted into the groove 2b and rigidly connected to the slider 3.

This block 10a is therefore substantially aligned to the slider 3 and is solidly movable there-with along the operative direction "A".

Preferably, the block 10a is inserted snugly in the groove 2b, such as to interfere with the lateral walls thereof, generating a frictional force tending to brake the movement of the slider 3.

The auxiliary damper 10 is preferably configured such as to increase its dissipating action in accordance with the displacement of the slider 3 along the operative direction "A".

Therefore, an increase in the collision force increases the dissipating action of the auxiliary damper 10, in cooperation with the damping body 4.

In fact, the increase of the impact force increases the value of the impulsive thrust on the slider 3, which slider 3 increases its displacement, encountering a growing resistance of the damping body 4 and the auxiliary damper 10.

In the illustrated embodiment, the groove 2b has a slightly tapered or rounded shape along the operative direction "A" in order to increase the force component perpendicular to the operative direction "A", thus increasing the friction force during the sliding of the block 10a.

In other words, the groove 2b has a pair of lateral walls in part inclined and in part extending in a reciprocal nearing direction.

Note that, the tapering is limited to small angles (in the order of tenths of a degree) such as to slow the auxiliary damper 10 without, however, preventing the movement.

In the illustrated embodiment, the block 10a is placed in a distal position from the end stop 6 with respect to the slider 3 and is connected to it (rigidly) by means of a bar (metal) 10b.

More precisely, the block 10a (when the slider 3 is in the first position) is located in the vicinity of the guide element 2 opposite the end stop 6.

Note that, in an alternative embodiment (not shown) the auxiliary damper may be the slider 3 itself.

Preferably, the device 1 comprises a measuring organ (not shown) of the displacement of the slider 3.

This measuring organ can be mechanical, such as an indicator (pointer) associated with a bar provided with measuring notches (e.g. centimetres or millimetres) arranged along the operative direction "A".

Alternatively, the measuring organ may be electric/electronic, provided with a displacement sensor or the like.

This arrangement has several advantages from the point of view of insurance, since it allows an expert officer to assess the violence of the impact and to estimate the physical damage that the passenger/driver could in theory have undergone.

In fact, once the slider movement and the resistance the damping body 4 (and possibly the auxiliary damper 9) opposes thereto are known, it becomes easy to calculate the impact force with which the vehicle 200 has been struck.

The present invention also relates to a frame 101 for a seat 100 for vehicles 200 (preferably motor cars).

As known, these seats 100 include the frame 101, preferably metal, wrapped in padding 102 for on-board comfort and also for reducing motion stress.

The frame 101 comprises a support structure 103 defining a seating plane "B" of a driver or passenger of the vehicle 200 connected to the platform 202 thereof.

In addition, the frame 101 includes a backrest 104 coupled to the support structure

103 and extending transversally thereto to define a support plane "C" of the vehicle driver or passenger's back.

The seating plane "B" is substantially parallel to (and spaced from) the floor 202 of the vehicle 200.

On the contrary, the rest plane "C" is transversal thereto (with an adjustable inclination using known adjusting means).

Preferably, the frame 101 of the seat 100 also comprises an adjustment group 105 of the position of the seat 100 itself with respect to the platform 202 of the vehicle 200, connected to the safety device 1.

The adjustment group 105 may be interposed between the frame 101 of the seat 100 and the device 1 or, alternatively, between the device 1 and the platform 202 of the vehicle.

In the illustrated embodiment, this adjustment assembly 105 is integrated with the device 1.

Preferably, in fact, the adjustment group 105 includes a skate 106 fixed unremovably to the support structure 102 of the frame 101 of the seat 100. This skate 106 is freely slidable with respect to the slider 3 along the operative direction "A". More precisely, the skate 106 is slidably coupled to the guide element 2.

Even more preferably, the skate 106 is defined by a plate 106a slidably coupled to the lateral wings 2b of the guide element.

The guide element 2 has a central portion (the groove 2b) associated with the slider 3 and a peripheral portion (the wings 2c) associated with the skate 106. In other words, the guide element 2 is a double guide. Moreover, the adjustment group 105 comprises an engaging organ 107 movingly interposed between the skate 106 and the slider 3 such as to couple them .

The engaging organ 107 is selectively movable, by a user (driver or passenger of the vehicle 200), between an engagement and a disengagement position in order to adjust the position of the seat 100.

More precisely, the engaging organ 107 comprises a tooth 107a engageable with the slider 3 such as to couple the slider 3 with the skate, or vice versa.

In the illustrated embodiment, the tooth engagement 107a is connected (hinged) to the skate 106 and is selectively engageable in a plurality of adjustment seatings 3a made in the slider 3.

Consequently, the skate 106 is rigidly connected (connectable) to the frame 101 of the seat 100.

In this light, the skate 106 defines at least in part the rigid connection means 7 between the slider 3 and the seat 100.

Alternatively, the engaging tooth could be connected to the slider 3 and the seatings might be made in the skate 106.

In the preferred embodiment, the engaging organ 107 also comprises a command portion 107b, grippable by a user (driver or passenger), which can be automated type (electrical/electronic/pneumatic/hydraulic) or manual (lever).

The frame 101 of the seat 100 also includes a shoulder-piece 108 having at least one plate 109 extending parallel to the support plane "C" and spaced from the backrest 104 in such a way as to be facing it.

More precisely, the plate 109 is movable towards or away from the backrest 104 along a direction parallel to the travelling direction "D" of the vehicle 200.

In this regard, the shoulder-piece 108 includes a plurality of dissipating elements 110 developing transversally to the support plane "C" (therefore parallel to the travelling direction "D" of the vehicle 200) and interposed between the plate 109 and the backrest 108 such as to deform following a shift of the plate 109 nearingly to the backrest 108, thus reducing the velocity thereof.

In this way, the transfer of force that the passenger or driver undergoes in the event of crash of the vehicle is reduced, helping to alleviate the whiplash effect. A further advantage of the shoulder-piece is to make the padding more compact and thus less yielding. The following is a description of a second embodiment of the present invention, which performs the same tasks as the first variant, and obviates the same technical problem in a way that is conceptually very similar, though structurally different. In this second variant of the present invention, illustrated in figures 5 to 16, the seat 300 comprises an energy absorption and dissipation system 302, freed to operate in a case of collision of the vehicle with an obstacle or another vehicle, and preferably positioned below the actual seat.

This system comprises shock-absorbing means 303 able to absorb and dissipate impact forces of different intensities. During a collision, in fact, the impact force generated depends on the speed and mass of the bodies (vehicles and/or possible obstacles) involved.

The shock-absorbing means 303 of the system 302 are active, i.e. they are instantly adjustable in terms of the load that they can absorb and dissipate, and they therefore vary in their ability to instantly react on the basis of the vehicle speed or also in the presence of any obstacles. This is enabled thanks to the presence at least one control unit 318 with which the energy absorption and dissipation system 302 is equipped, and also thanks to the sensors 304 which cooperate with the shock-absorbing means 303 of the seat 1 and regulate the proper functioning thereof.

The sensors 304 instantaneously detect at least the speed of the vehicle and any obstacles approaching the vehicle. This control is necessary, for example, in a case of a crash with the vehicle stationary, a condition in which the shock-absorbing means 3 are normally unloaded and in which they must instantaneously go into a configuration that is suitable for absorbing the impact.

The above-mentioned shock-absorbing means 303 are arranged parallel to the ground, below the seat, along the direction of movement of the motor vehicle, and are both front and rear facing to respectively cushion frontal collisions or rear crashes, or trans versally thereto for any lateral impacts.

The shock-absorbing means 303 are advantageously inserted into a frame structure 319 to which the seat 300 is constrained.

The shock-absorbing means 303 are normally in an extended configuration as shown in figures 5, 7, 8 and 11, while they are compressed and deformed as a result of the collision (figures 6, 9, 10, 12).

Very important is the presence of blocking means 305, which are able to maintain the shock-absorbing means 303 in position assumed following the collision. In fact, the aforementioned shock-absorbing means 303 are spring elements. Following the impact, if the shock-absorbing means 303 were not blocked in the new deformed configuration, they would tend to release the energy stored during the collision.

The spring elements that make up the shock-absorbing means 303 can be, for example, of a mechanical type (helical springs or the like), pneumatic, hydro- pneumatic or gas (air springs, gas springs or the like). These are just some examples of types of damping means which can be used. However, other types of damping means are not excluded, which can perform the same function as described herein below_;

Regardless of the type, each spring element exhibits at least a rod 306 and a body 307, constrained to the seat 300. The rod 306 and the body 307 are reciprocally movable and slidable with respect to one another.

The relative sliding between the rod 306 and the body 307, and its interaction with the body 307, described in various embodiments in the following, enable the absorption and dissipation of the energy released during the impact.

Depending on the length of the rod 306, the spring elements can be divided into main spring elements 310 and secondary spring elements 320. The main spring elements 310 have a long rod 306 that extends from the body 307, then from the seat 300, up to the front side, or to the rear side or to the lateral side of the vehicle such as to enter into action and start the run thereof right from the very first instant of the impact. The spring elements (in particular the primary spring element 310) are preferably arranged below the seat, in a lateral position with respect to the lower base of the seat.

At the free end 306a, the rod has a plate-like element 306b incorporated, for example, in the front or the rear bumper or in the lateral side of the cockpit. This plate member 306b has a large impact surface area such as to enable conveying the greater part of the impact onto the rod.

The secondary spring elements 320, however, are advantageously arranged below the seat, in a central position midway between two respective main spring elements 310. The secondary spring elements 320 exhibit a short rod 306 that extends from the body 307, and thus from the seat 1, to a bar 308 that is transversal to the laterally-located main spring elements 310.

Each secondary spring element 320 absorbs the impact energy in the final stage, when the main spring elements are by now collapsed and in the end position (figures 6, 9 and 10).

As mentioned above, the spring element, both main and secondary, additionally comprises, apart from the rod 306, a body 307 which interacts with the rod 306. In a preferred but not exclusive configuration, shown in figures 5-10, the body 307 comprises at least a cylinder 309 internally of which the respective rod 306 slides. In this configuration, the spring element is of the pneumatic type, the oil- pneumatic type or gas-operated.

The cylinder 309 is therefore constantly connected to a fluid-dynamic loading device 311 suitable for instantly loading or unloading the internal volume of the cylinder 309, on the basis of the parameters detected by the sensors connected to the shock-absorbing means 303. These parameters are the instantaneous speed of the vehicle and/or the distance thereof from an obstacle.

The energy absorption and dissipation system 302 additionally includes at least one valve, not illustrated, associated with each spring element 310, 320, for intercepting and/or allowing passage of the gas flow in the cylinder 309. This valve may be mechanical or electronic, and in particular it can be a solenoid valve (which can be electronically controlled).

The fluid-dynamic loading device 311 comprises a compressor. The compressor is suitable for instantly loading or unloading the internal volume of the cylinder 309 on the basis of the parameters detected by the sensors connected to the shock- absorbing means 303.

With reference to figure 16, the fluid loading device 11 advantageously comprises a closed-circuit pneumatic system in turn comprising:

- at least a main tank 410 preloaded with compressed gas (preferably compressed air) and connected to at least a valve 111 (preferably a solenoid valve), in turn operatively connected to one or more spring elements 310, 320;

- at least a line 412 for gas in discharge from the one or more spring elements 310, 320 towards the main tank 410.

The at least a valve 111 can coincide with the valve associated with each spring element 310, 320.

The gas discharge line 412 preferably leads to at least an additional tank 413. The additional tank 413 is then in turn connected with the at least a main tank 410. One or more service valves (not illustrated) can operate on the discharge line 412 of the gas (and/or, if the additional tank 413 is present, between the additional tank 413 and the main tank 410) for managing the outflow of gas from the spring elements 310, 320 and its re-storage in the main tank 410.

The closed-circuit pneumatic system can comprise a plurality of main tanks 410 and/or, where appropriate according to requirements, a plurality of discharge lines 412 for the gas, and/or a plurality of additional tanks with connected service valves. At least a main tank 410 can advantageously be provided, as well as at least an additional tank 413 and an additional discharge line 412 of exhaust gas for each spring element 310, 320.

The closed-circuit pneumatic system is suitable for instantly loading or unloading the internal volume of the cylinder 309, on the basis of the parameters detected by the said sensors connected to the shock-absorbing means 303.

The spring elements 310, 320 are loaded from the main tank 410. In the discharge stage, the spring members 310, 320 newly discharge the gas into the main tank 110 via the discharge line 412 (and, where present, via pre-accumulation in the additional tank 413).

In the absence of the compressor, the closed-circuit pneumatic system can be used pre-loaded with fluid.

At least a compressor (indicated in figure 16 with reference numeral 414) can advantageously be included, to assist the discharge of the gas into the main tank 410 and/or to maintain the gas pressure in the tank 410 at the level required by the functioning of the system (possibly drawing in air from outside). To this end, the tank 410 may be suitably sensorized with pressure detectors. The use of a closed- circuit pneumatic system (possibly assisted by the compressor) in the phases of loading and unloading of the spring members 310, 320 presents, compared to use only the compressor, the advantage of a greater rapidity of reaction to the conditions of the vehicle (in particular, to demands that may arrive via the control unit 318 of the energy absorption and dissipation system 302).

The management of the fluid-dynamic loading device 311 may be entrusted to a relative control unit. This control unit can be integrated in, or may coincide with, the control unit 318 of the energy absorption and dissipation system 302.

Instead of having a single chamber inside the cylinder 309, a plurality of spring elements 310, 320 can be provided, connected together in series and activated in succession: a spring element is activated at the moment when the preceding spring member reaches end position.

It is also possible to provide a plurality of spring elements 310, 320 connected to one another in parallel. The two configurations of spring elements 310, 320 may be mixed with each other and/or coupled and/or used in series or in parallel, according to needs.

Once the final end position has been reached, the spring members are locked in their deformed position by suitable blocking means 305.

The blocking means 305 serve to keep the rod 306 in a deformed position as a result of the collision and to avoid the reaction of the spring member 310, 320 which would tend to return the rod 306 into the initial position with a rebound effect, in order to return the energy absorbed.

The blocking means 305 may be mechanical, electronic, operated by sensors, operating by compressed air or magnetic.

In this configuration the blocking means 305 are represented, for example according to a preferred but not exclusive embodiment, by a plurality of snap-type protrusions 313, arranged along each rod 306, suitably shaped so as to allow the insertion of the rod 306 within the cylinder 309 and at the same time prevent slippage. Once the rod 306 is within the cylinder 309, the projections 13 interfere from the inside with the inlet section of the cylinder 309, preventing the rod from sliding in the opposite direction.

Other types of blocking means 305 may be provided in place of the projections described above.

In general terms the blocking means 305 are preferably mechanical elements, which interfere with the sliding of the rod 306, thus increasing the friction with the cylinder 309 so as to further brake the travel and dissipate energy.

In use, under normal driving conditions, the energy absorption and dissipation system 302 is constrained to the seat 300 and presents the rods 306 stretched and the cylinder 309 constantly loaded and unloaded from the fluid-dynamic loading device 311 on the basis of the values of speed or the speed and proximity to an obstacle detected by the sensors.

These sensors 304 constantly send the data collected to a control unit 318, on the basis of which the control unit 318 sends a signal to the valves and the fluid- dynamic loading device 311 for loading or unloading the gas or the air inside the cylinder 309. In this way the weight that the spring elements (rod and cylinder) are able to withstand increases or decreases.

In a case of an accident, the various spring elements are at least in part ready to absorb the energy released by the impact, to dissipate it by friction and the heating of the gas and then block the structure in the collapsed configuration to avoid the rebound effect.

The secondary spring element 320 serves to dampen the whiplash effect, as it is an additional damping element fitted to the seat and ready to absorb also the residual impact energy, at the final moment, when the effect of the impact effects are felt at the seat location.

In a second embodiment, of which only a detail is shown in figures 11-14, the energy absorption and dissipation system 302 includes at least one spring element 310, 320 comprising a body 307, constrained to the seat, from which at least one rod 306 departs, preferably four, which at least one rod 306 is made of metal with a plate member 6b at the end thereof connected to the front or rear bumper or to the lateral body of the vehicle. In this configuration, the blocking means 305 are located below the rods 306, the body 307 and the plate member 306b to which they are constrained.

In particular, the blocking means 305 comprise a bar 331, constrained to the plate member 306b and extending up to the body 307 below the rods 306. The bar 331 exhibits a plurality of teeth 332 projecting and facing towards the rods 306.

Around each rod 306, the spring element 310, 320 exhibits a respective elastic device 333 such as a spring of the mechanical type. The various elastic devices 333 exhibit different dimensions and resisting or compressive forces, such as to be able to calibrate the reaction force provided by the impact on the basis of the entity of the impact.

The body 307 affords a hole 334 for each rod 306, through which only the rod 306 or the^{^}rod 306 and the respective elastic device 333 located there-about travels, depending on whether that spring element is activated or not.

The selective activation of one, several or all of the spring elements is obtained by a closing element 335 with which each hole 334 of body 307 is fitted.

This closing element 335 is commanded and actuated by a control unit 318 connected to suitable sensors 304, as in the case described above, which detect the instantaneous values of speed and/or speed and distance from possible obstacles. On the basis of the detected values, the control unit selectively (or simultaneously) activates one or more spring elements activating the closure elements 335, thus preventing the passage of the elastic device 333 through the hole 334. Depending on the speed of travel one_> some or all of the closure elements 335 are activated, and then a suitable combination of spring elements is selected, capable of reacting to the more or less intense impact forces. A tab 336 projects from the body 307, which tab 336 is part of the blocking means 305.

The tab 336 is hinged to the body 307 and is raised on the passage of the teeth projecting from the bar 331 , lowering and positioning itself between two successive teeth immediately after passage of one thereof.

Therefore, this tab 336 blocks the relative movement between the rods 306 and the body 307, while maintaining the spring element compressed. Relative sliding in the opposite direction between the body 307 and the rods 306 is prevented.

In this configuration too the spring elements can be arranged aligned in the travelling direction, positioned frontally or posteriorly, or transversally to the travelling direction, in order to cushion lateral impacts.

As with what was explained and described for the air or gas spring configuration, main spring elements can be present which absorb the impacts at least in their first stage and which extend from the seat at the front or the back of the motor vehicle, or secondary spring elements, prevalently for damping the impact in the final stage and reducing the whiplash.

In a variant that is not illustrated, the rods may be telescopic, so as to shorten the length thereof and adapt the system to different motor vehicles.

Additional rubber inserts may also be present, which further dampen the impact. The calibration of the seats and the entire the energy absorption and dissipation system 302 is realised on the basis of the weight of the vehicle and the speeds reached. "

The invention achieves the intended aim arid objectives, as the device considerably reduces the energy transmitted to the seat (and thus to the passengers) by increasing the time of the impact, thereby reducing the impact force absorbed.

Further, the plastically deformable structure of the damping body prevents the elastic return of the slider and therefore of the seat.

Moreover, the presence of a single deformable and replaceable damping element greatly facilitates the device reactivation operation following an impact.

Furthermore, the device thus formed is particularly economical and can be manufactured on a large scale with modest costs for the producer.

As regards the second variant, the possibility of instantaneously adjusting the reaction force that the damping means need to apply enables the structure of the entire the energy absorption and dissipation system 302 to be made lighter. In this variant the invention has the particular characteristic of calculating and assessing the potential violence of a collision and, therefore, of opposing it actively with the relative power; the simple frames or the known structures of the vehicle (either made of sheet metal or other materials) are not able to do this.

Claims

1. A safety device for a seat (100) of a vehicle (200), to be installed on a seat (100) of said vehicle (200), characterised in that it comprises:

- a guide element (2) developing along a main axis thereof such as to define an operative direction (A) of the device and provided with rigid connecting means (5) with a platform (202) of said vehicle (200);

- an end stop (6) rigidly connected to an end portion (2a) of the guide element (2);

- a sliderslider (3), slidably associated to said guide element (2) such as to slide with respect thereto along said operative direction (A) either nearing to or distancing from said end stop (6); said sliderslider (3) being provided with rigid connecting means (7) to said seat (100);

a damping body(4) operatively interposed between the slider (3) and the end stop (6) along said operative direction (A.) and having a ductile structure configured such as to plastically deform following a displacement of the slider (3) along the guide element (2), in a direction nearing to or distancing from said end stop (6), in order to oppose said displacement in order to reduce a velocity thereof.

2. The device according to claim 1, characterised in that it exhibits a passive configuration, in which the damping body (4) is maintained undeformed, and an active configuration in which the damping body (4) plastically deforms such as to reduce a relative velocity between said slider (3) and said end stop (6); said device being configured such as to pass from the passive configuration to the active configuration in response to an impulsive thrust action parallel to said operative direction (A) exerted on said slider (3) and having an intensity greater than a predetermined threshold value.

3. The device according to claim 2, characterised in that a state of deformation of the damping body (4) is proportional to the intensity of said impulsive action.

4. The device according to claim 2, or claim 3 characterised in that it comprises at least a blocking member (8a) associated to the slider (3) and movable between a blocking position, in which it prevents displacement of said slider (3) along the guide element (2), and a release position in which it does not interfere with the slider (3); said blocking member (8a) being configured such as to pass from the blocking position to the releasing position following exceeding of said threshold value of the impulsive action.

5. The device according to claim 4, characterised in that the blocking member (8a) 5 is associated to elastic means (9) that are movable transversally to the operative direction (A) in order to maintain the blocking member (8a) in said blocking position.

6. The device according to claim 5, characterised in that the blocking member (8a) i o exhibits a rounded conformation such as to transmit at least a part of the thrusting action of the slider (3) in the operative direction (A) to the elastic means (9).

7. The device according to any one of the preceding claims, characterised in that it comprises an auxiliary damper (10) associated to the slider (3) and configured

15 such as to collaborate with said damping body (4) along the operative direction (A).

8. The device according to claim 7, characterised in that said auxiliary damper (10) is a friction damper.

20

9. The device according to claim 8, characterised in that said auxiliary damper (10) is configured such as to increase the dissipating action thereof according to the displacement of the slider (3) along the operative direction (A).

25 10. A frame for a seat ( 100) of a vehicle (200), comprising:

- a support structure (103) defining a seating plane (B) for a driver or a passenger of said vehicle (200);

characterised in that it comprises a safety device (1) according to any one of the preceding claims, wherein said support structure (103) is rigidly connected to said 30 slider (3) by means of said rigid connecting means (7).

11. A frame for a seat (100) according to claim 10, characterised in that it comprises a backrest (104) coupled to said support structure (103) and developing transversally thereto such as to define a rest plane (C) for the vehicle driver or 35 passenger's back; said frame further comprising a shoulder-piece (108) provided with at least a plate (109) developing parallel- to the rest plane (C) and distanced from the backrest (104) in such a way as to be facing the backrest (104) and a plurality of dissipating elements (110) developing transversally to the rest plane (C) and interposed between said plate (109) and said backrest (104) such as to 5 deform following a displacement of the plate (109) nearingly to the backrest (104), reducing a velocity thereof.

12. A frame for a seat (100) according to claim 10 or 11, characterised in that it comprises an adjustment group (105) of the position of the seat (100) connected to i o the safety device (1).

13. A frame for a seat (100) according to claim 12, characterised in that the adjustment group (105) comprises:

- a skate (106) fixed unremovably to the support structure (103) and freely slidable 15 with respect to the slider (3) along said operative direction (A);

- an engaging tooth (107) connected to the skate (106) or the slider (3) and selectively engageable in a plurality of adjustment seatings (3a) realised respectively in said slider (3) or in said skate (106).

20 14. A vehicle seat characterised in that it comprises an energy absorption and dissipation system (302), in a case of collision of the vehicle with an obstacle or another vehicle, comprising shock-absorbing means (303) able to absorb and "dissipate impact forces having different intensities and blocking means (305) able to maintain said shock-absorbing means (303) in the position assumed following 5 the collision.

15. The seat according to claim 14, characterised in that said shock-absorbing means (303) are instantaneously adjustable for a load they are able to absorb and dissipate; said shock-absorbing means (303) being arranged parallel to a ground, 0 along a movement direction (D) of the vehicle or transversally thereof.

16. The seat according to claim 14 or 15, characterised in that said shock- absorbing means (303) cooperate with sensors (304) suitable for instantaneously detecting at least a velocity of the vehicle; said sensors (304) cooperating with a control unit (318) able to regulate a functioning of said shock-absorbing means (303).

17. The seat according to any one of claims from 14 to 16, characterised in that said blocking means (305) are mechanical, electronic, sensorised, operating by compressed air or are magnetic means, and block a relative position between the rod (306) and the body (307) following the collision.

18. A vehicle, comprising:

- a support framework (201) provided with a platform (202);

- at least a seat (100) connected to said platform (202);

characterised in that it comprises a safety device (1) according to any one of claims from 1 to 10, operatively interposed between said seat (100) and said platform (202), wherein the slider (3) is rigidly connected to said seat (100) by means of said rigid connecting means (7) and the guide element (2) is rigidly connected to said platform (202) by means of said rigid connecting means (5).

19. The vehicle according to claim 18, characterised in that the operative direction (A) of the safety device (1) is substantially parallel to an advancement direction (D) of the vehicle (200).