EP0342089B1 - Buckle for safety belts - Google Patents

Description

The present invention relates to seat belt buckles and, more particularly, those of them intended for motor vehicles, preferably land vehicles.

As we know, motor vehicles in particular on land are equipped with seat belts which must meet a draconian specification, established, most often, by the public authorities, at least in part.

Under normal conditions, when a seat belt does not act to restrain an occupant of the vehicle in its seat as it does in the event of a violent impact, the strap of the belt normally rests against the body of the wearer, if necessary. under the action of a very small tension exerted by a return mechanism of a reel. In such conditions it is relatively easy to open the buckle of a belt.

In other circumstances, in particular when a vehicle following an accident is found to have been tipped, the strap of the seat belt is subjected to a tension which can be notably higher; this tension is that which is, for example, exerted by the weight of an occupant who is supported or suspended by the strap in the event of the vehicle overturning. It is necessary that in such conditions the seat belt buckle can be opened by the occupant himself or a third party relatively easily in order to release the person thus maintained. This is difficult because in such a situation the belt tension is around 50 daN to around 60 daN and one must be able to open the loop by exerting a force of 25 daN which is practically extremely difficult to develop.

In addition, it is imperative that during a severe shock proper, when the seat belt retains the occupant in his seat and his tension exceeds 100 daN during the brief moments of absorption of kinetic energy, the locked buckle does not open unexpectedly at a particularly untimely moment, otherwise its effectiveness will be negated. To achieve this we have already imagined loops which, once locked, are kept locked in this state.

A buckle for a seat belt with a locking lock is, for example, described in French patent 2,349,296 and its certificate of addition 2,379,995.

Another solution is described in the German document DE 33 44 041. According to this solution, an elastically deformable latch is used to lock the loop in the closed position when it is subjected to excessive stresses.

These documents disclose different variants of seat belt buckles with locking interlock. All the embodiments which are exposed meet the standards but their realization is somewhat complex. If such a complex embodiment does not call into question the reliability of these loops, it is however detrimental to a relatively low manufacturing and mounting cost.

The object of the invention is to produce a buckle for a seat belt, in particular for a motor vehicle with locking locking which, all year round, offers the advantages of the buckles which have just been mentioned does not have the disadvantages, in particular economic ones.

The subject of the invention is a buckle for a seat belt, in particular for a land motor vehicle, intended to join a strap at one point. anchor of the type indicated in the preamble to the main claim which mentions the elements necessary for the invention and disclosed by the aforementioned German document, and whose distinctive features emerge from the characterizing part of this claim.

• la Fig.1 est une vue perspective éclatée d'un mode de réalisation d'une boucle de ceinture de sécurité selon l'invention ;
• la Fig.2 est une coupe longitudinale de la boucle illustrée sur la Fig.1 une fois assemblée, représentée en position verrouillée sans son pène ;
• les Fig.3A, 3B et 3C sont des vues schématiques partielles illustrant le fonctionnement du mode de réalisation de la boucle selon l'invention illustrée sur les Fig.1 et 2 ;
• les Fig.4A et 4B sont d'autres vues fragmentaires illustrant le fonctionnement de ce mode de réalisation :
• La Fig.5 est une vue analogue à celle de la Fig.1 avec arrachement local d'une autre variante de réalisation d'une boucle de ceinture selon l'invention ;
• la Fig.6 et une coupe longitudinale d'une boucle selon la Fig.5 assemblée, en position verrouillée sans pène analogue à la Fig.2 ; et
• la Fig.7 est une vue perspective du seul bouton d'actionnement des modes de réalisation des Fig.1 et 5 en montrant l'essentiel de sa configuration.

Other characteristics of the invention will appear on reading the description and the claims which follow and on examining the appended drawing, given only by way of example, where:

• Fig.1 is an exploded perspective view of an embodiment of a seat belt buckle according to the invention;
• Fig.2 is a longitudinal section of the loop illustrated in Fig.1 once assembled, shown in the locked position without its bolt;
• Fig.3A, 3B and 3C are partial schematic views illustrating the operation of the embodiment of the loop according to the invention illustrated in Fig.1 and 2;
• Fig.4A and 4B are other fragmentary views illustrating the operation of this embodiment:
• Fig.5 is a view similar to that of Fig.1 with local cutaway of another variant making a belt buckle according to the invention;
• Fig.6 and a longitudinal section of a loop according to Fig.5 assembled, in the locked position without bolt similar to Fig.2; and
• Fig.7 is a perspective view of the single actuation button of the embodiments of Fig.1 and 5 showing the main part of its configuration.

Since the buckles for a seat belt for a motor vehicle, in particular a land vehicle, are well known in the art, we will only describe below what relates directly or indirectly to the invention. For the rest, the specialist in the technique considered will draw on the conventional solutions at his disposal to deal with the particular problems with which he is confronted.

In the following, the same reference number will always be used to designate a homologous element whatever the embodiment in question.

As can be seen in particular in FIGS. 1 and 5, a buckle for a seat belt, in particular for a motor vehicle according to the invention, intended to join a strap to an anchor point, consists, inter alia, of a bolt 10 and a keeper comprising, a base 20 and carried by the latter a lock 30, an ejector guide 40, an actuation button 50 and, preferably, a protective envelope 60. In certain cases this protective envelope contains also, if necessary, a detector 80 for closing the loop and a lighting device 90.

For the convenience of the description, each of the constituents of this buckle for a seat belt according to the invention.

The bolt 10 comprises a body 101 provided with an extension 102. The body 101 is pierced with a passage 103 intended to receive a strand of a safety strap, not shown. The housing 102 is pierced with a cutout 104 intended to cooperate with the lock 30 as will be seen later.

The base 20 is in the form of a U-shaped part with a bottom 201 which brings together two practically parallel sides 202. In the sides are formed two interior bosses 203 facing each other. This bottom, these sides and these bosses define a channel 200 intended to receive the extension 102 of the bolt, as will be understood later.

In the bottom 201 is formed an opening 210 which consists of a slot 211 at one end, followed by a middle window 212 and terminated by an opening 213. We will understand the role played by each of these parts of the opening 210 thereafter. In the bottom is also made a notch 209. This bottom is also pierced with a hole 214 to receive a connection with an anchor point, not shown.

As can be observed, each of the sides 202 is also provided with a manhole 233, a light 204, a protrusion 205, a bearing 231 with a joint 230 as well as a turned ear 220 towards the exterior, which we will come back to later.

The lock 30 is in the manner of a plate on one of the faces of which is formed a spout 301 and on two of the sides of which there are also wings 302 and supports 303. Oriented in the same direction, the plate also carries a base 320 provided with a nipple 321. The sides of this plate where the wings 302 and the supports 303 are located carry pins 310 of the joint 230 and form legs 340, as shown.

The ejector guide 40 comprises a shoe 410 in the form of a fork with two teeth followed by a stirrup 420 which is extended by a heel 430 in which are formed on two sides of the grooves 440. This shoe and this stirrup define a housing 400 intended to receive the end of the extension 102 of the bolt 10, as will be understood later. The ejector guide also includes a nipple 450.

As can be seen, the actuation button 50 comprises a front 501 and two side walls 502. In the front 501 is provided a mouth 510 for the passage of the extension 102 of bolt 10.

As can be seen, the side walls 502 are provided with elastic fingers 520 which each carry a tooth 521. Each of the teeth 521 has a bevel 522 and a shoulder 523. The side walls 502 also have grooves 503 intended to receive the ears 220 of the base. The actuation button 50 also carries a stud 504 and on one of its side walls 502 a bar 530 with a rib 531 to which we will return. All this is clearly illustrated in Fig. 7.

The protective envelope 60 is in the manner of a housing 600 in which is placed, if necessary, a stud 601 as shown in FIG. 2. This envelope also carries a relatively rigid elastic lip 602.

As can be seen, the housing 600 is crossed by a rod 610 which can slide therein relatively freely, pierced near its end with a hole 611 intended to receive an eyelet, rivet or analog 612 in order to join this rod to the base 20 using the hole 214. This rod makes it possible to join the keeper of the loop according to the invention to an anchor point, not drawn, of the structure of a vehicle, as it is classic.

The loop according to the invention comprises control and blocking means 70. These control and blocking means 70 consist of a cam 75 formed on each of the walls 502 of the actuation button 50 and of a cam follower 73 carried by each of the wings 302 of the lock 30. These control and blocking means 70 also comprise an edge 71 on each of the wings 302 of the lock 30 and a locking notch 72 formed in each of the slots 204 formed in the sides 202 of the base 20.

The loop according to the invention also includes, if necessary, a closing detector 80 housed in the protective casing 60. This detector comprises a switch 800, the operating member 801 of which is placed on the path of the latch 30 so as to be able to be actuated by one of the wings 302 of the latter.

The lock according to the invention also includes, if necessary, a lighting device 90 housed in the protective envelope 60. This lighting device is arranged so as to illuminate at least the channel 200 of the bolt 10.

The detector 80 and the lighting device 90 are mounted by any suitable conventional technique, for example on a common support 89 fixed on the base 20 using a snap-fit assembly for example, not drawn, intended to cooperate with an orifice 88 of the base.

A spring 460 exerts a stress elastic on the latch 30 and on the ejector guide 40 and a spring 540 exerts an elastic stress on the actuation button 50.

The components which have just been described and which are illustrated clearly and precisely in particular in FIG. 1 and FIG. 7 which it suffices to refer to in order to know the exact proper configurations thereof, are assembled as illustrated in FIG. .2 or 6, depending on the embodiment.

As can be understood by examining FIGS. 1 and 2 in particular, the ejector guide 40 has been engaged in the opening 210 of the bottom 201 of the base 20 by first passing through the opening 213 with its heel 430 then by sliding it into the window 212 so that its grooves 440 can slide there against the edges thereof. Then the spring 460 is threaded onto the stud 450 and the lock 30 is suitably oriented while engaging its journals 310 in the bearings 231 and its beak in the slot 211, then the spring 460 is released so that it engages on the stud 321 of the base 320 of the lock 30. The supports 303 of the lock direct and center the latter between the sides 202 of the base.

This done, the actuating button 50 is engaged so that its grooves 503 come over the ears 220 over which it is free to slide. To do this, the fingers 520 are discarded elastically, the teeth 521 of which engage in the manholes 233. The bevels 522 of the teeth 520 facilitate this engagement.

The shoulders 523 serve as a stop to prevent the actuation button 50 from separating from the base 20 under the pressure of the spring 540 which has been threaded onto the pins 504 and 601 or 321. In the other direction, the stroke of the actuation button 50 is limited by the cooperation of the inner face of its front 501 and the parts of the sides 202 of the base which delimit the lights 204 and are directed towards the front.

This done one engages the eyelet or the rivet 612 in the holes 214 and 611 of the base 20 and of the rod 610 respectively in order to join these two constituents.

The spring 540 is then placed on the stud 504 and the housing 600 is approached from the protective envelope 60 which is immobilized by any suitable technique in the position where it is illustrated in FIG. 2, in this case by the click of the retaining lip 602 in the notch 209.

Due to the configuration given to the joint 230, the pins 310 of the lock 30 can rotate, without practically sliding therein, in the bearings 231 of the base 20. These bearings 231, as shown, have an L-shaped configuration inverted by so as to facilitate the assembly and to keep the pins 310 trapped. The games allow assembly and manual or automatic assembly as well as safe operation. It can therefore be seen that the latch 30 is mounted on the base 20 in a manner which allows it to move only by tilting in order to be movable between at least two positions towards which it is resiliently urged by the spring 460. The latch 30 can therefore move between a first release position where the bolt 10 is unlocked and a second retaining position where the bolt 10 is locked to the strike by the bolt 30. As will be understood later, this unhindered tilting of the lock on the base also results from the configurations own data at the spout 301 of the lock 30 and at the slot 211 of the opening 210 of the bottom 201 of the base 20 as well as their relative positions. In its second retaining position where the lock 30 locks the bolt 10 on the keeper, the bolt is pushed back by the ejector guide 40 against the lock so that the spout 301 thereof and the edge of the cutout 104 touch without the spout 301 touching the slot 211 of the base 20, however, a well-defined predetermined clearance g existing between them.

As we have seen, the ejector guide 40 is housed in the opening 210 of the bottom 201 of the base 20 so that its grooves 440 rest with play against the edges of the window 212 where it can slide. It is therefore seen that the ejector guide can move in translation so as to be movable between a rest position towards which it is normally resiliently urged by the spring 460 and which it occupies when the latch 30 is in its first position and a armed position which it occupies when the latch 30 is not in its first position.

The actuation button 50, thanks to the cooperation of its grooves 503 with the ears 220 of the base 20 can move therein in translation so as to be movable between an inactive position towards which it is normally elastically stressed by the spring 540 and a position in which it passes the latch 30 in its first position.

We will now refer to Fig. 3 and 4 where the embodiment which has just been described is illustrated in different phases of its operation.

The different Fig. 3 are schematic and only part of the components of a loop according to the invention are illustrated there.

In Fig.3A, the components are illustrated in the relative positions they occupy either for hooking the bolt on the keeper for closing the loop or immediately following the opening of the loop. In the illustrated position where the actuating button 50 is not shown, the latch 30 is illustrated in its first position and the ejector guide 40 in its rest position. If we now direct the bolt towards the strike by engaging its extension 102 in the mouth of the button to make it enter the channel 200 of the base 20 then in the housing 400 of the ejector guide 40 and that it pushes all the way, the ejector guide 40 is gradually pushed back towards its armed position against the stress of the spring 460 which is itself progressively compressed. By compressing, the spring 460 develops an increasing torque on the latch 30 which, initially biased clockwise (Fig.3A) by this thinly banded spring, swings freely counterclockwise around its articulation 230 as soon as it is crossed. balance point. The buckle then takes its locked position illustrated in Fig.3B. In this situation the latch 30 occupies its second position and the ejector guide 40 occupies its armed position.

As is easily understood, at the moment when the lock 30 swings around its articulation 230, its beak 301 engages in the cutout 104 of the extension 102 of the bolt 10 and in the slot 211 of the opening 210 formed in the bottom 201 of the base 20. The calibration of the spring 460 is chosen so that when the lock 30 switches from its first to its second position, the spout is in line with the cutting the bolt without risking meeting the edges of the latter which could hinder its travel. It is only when the bolt is released that the ejector guide 40 can move the bolt back to make it lean against the beak of the bolt, as illustrated in Fig.3B. As can be seen in this Fig.3B a determined and prefixed clearance g exists between the spout and the slot in which it is engaged.

If the locked loop, the components of which are placed in the relative positions illustrated in Fig. 3B, is now subjected to a tensile force T which exceeds a determined value and which tends to open it, the bolt being torn from the keeper , the bolt 10 drives the latch 30 to a third locking position as shown in Fig.3C.

As can be seen then, the bolt now attaches directly to the base; the clearance g is absorbed. A double cooperation is manifested, on the one hand the spout 301 is applied against the slot 210 and on the other hand the edges 71 of the wings 302 engage in the notches 72 of the lights 204 formed in the sides 202 of the base 20. The position is then that illustrated in Fig.3C.

If the tensile force T on the bolt and transmitted to the bolt develops a component which would tend to move the bolt from its third position where it is illustrated in Fig.3C to its first position illustrated in Fig.3A, it would be prevented by the engagement of the edges 71 in the notches 72 which ensures the locking of the lock in the locked position. This gives the assurance that the closed and locked loop cannot accidentally and inadvertently open at the precise moment. where it must fulfill its office: imperatively retain the occupant in his seat.

The lock is designed so that its beak 301 and its legs 340 are elastically deformed to neutralize the initial predetermined play g when such traction exceeds a selected predetermined value, passing from its second to its third position.

We will now refer to Fig.4A and 4B where this embodiment of the loop according to the invention is illustrated schematically in different positions which correspond to the opening phase of the loop.

To open the closed and locked loop and move it from the situation where it is illustrated in Fig.3B to that where it is illustrated in Fig.3A, the actuation button 50 is pressed against the biasing of the spring 540. By doing this the actuation button leaves its inactive position, towards which it is normally biased by the spring 540, and goes to an active position in which it causes the latch 30 to pass into its first position.

As can be understood and seen, moving back from its inactive position to its active position, the grooves 503 sliding against the ears 220, the cams 75 of the actuation button 50 come into contact with the cams 73 of the wings 302 of the latch 30 they raise. The lock swings around its articulation 230 against the torque developed by the spring 460. By tilting the spout 301 emerges from the cutout 104 of the bolt which is released and pushed back by the ejector guide 40 out of the keeper. The tilting of the lock is limited by the encounter of one of the wings 302 with the rib 531 of the bar 530 of the actuation button 50.

In the position where the loop is illustrated in Fig.3B there are only two points of contact between the latch 30 and the base 20; these points are those which are located at the joint 230. This situation is that which prevails when the traction exerted on the loop does not exceed a value which is of the order of approximately 50 to 60 daN. This is the case where an occupant is "suspended" by the belt strap in a vehicle poured to the side or overturned on the roof; it is the weight of this occupant which exerts traction on the loop.

In the situation illustrated in Fig.3C which corresponds for example to that where the traction exerted on the loop is greater than 100 daN during the brief moments of a relatively brutal collision, we see that the number of points of contact between the latch and the base has been significantly increased. In fact, in addition to those which result from the hinge 230 previously indicated, there are added the two points of contact of the edges and notches as well as that of the spout with the slot in the opening of the bottom.

We will now refer to Fig.5 and 6. We can immediately see that the essential difference lies in the fact that the spring 540 which resiliently biases the actuation button 50 no longer acts directly on the housing 600 of the envelope protective 60 but on a stud 331 with a tab 330 formed on the latch 30 and, more particularly, on the face of the plate thereof which is opposite to that on which the spout 301, the wings 302 and the base 320. For the rest the operation is exactly the same.

The loop closing detector 80 is mounted as shown in the figures in the drawing. This detector comprises, for example, a microswitch 800 whose operating member 801 is placed on the path of one of the wings 302 of the lock. This switch is such that when the lock occupies its first release position where the bolt is unlocked, the switch is actuated to implement an undrawn signaling circuit. On the other hand, when the lock does not occupy its first position, its wing 302 no longer acts on the operating member of the switch and the latter is at rest. This signaling circuit is of any type known to trigger an acoustic and / or light signal in the vehicle indicating that an occupant of the vehicle has not put on and fastened their seat belt. This switch can be of the contact-work or contact-rest type.

The lighting device 90 which comprises a miniature filament lamp or an electroluminescent diode for example, is oriented so as to preferably illuminate the channel 200 and the mouth 510 in order to facilitate the insertion of the bolt into the spoils. The lighting and extinction of this lighting device are for example controlled simultaneously with the lighting and extinction of the overhead light of the motor vehicle during the opening or closing of the doors or else during the implementation. parking and / or vehicle traffic lights. The classic electrical circuit is not drawn.

The ejector guide 40, the actuation button 50 and the protective cover 60 are, for example, made of synthetic material and are obtained for example by molding. The actuation button 50 is preferably translucent so as to make the radiation from the lighting device perceptible.

The housing 600 of the protective envelope 60 can be made in one piece from molding or made in two half-shells assembled in any suitable known manner.

The bolt 10, the base 20 and the latch 30 are preferably made of metal and obtained by stamping, cutting and bending of metal sheets as is known. If we compare the embodiments of Fig.1 and 5 we see that the lock 30 of Fig.1 is easier to manufacture than that illustrated in Fig.5. In this regard, special care must be taken in choosing the material from which the lock 30 is made so that it has the elasticity necessary for the invention. The value of the clearance g , the dimensions and the sections of the beaks and legs are closely dependent on the mechanical properties of this material and the choice of the latter is also dependent on the manufacturing techniques chosen, themselves linked to the equipment and tools available.

We understand all the advantages of the seat belt buckle according to the invention which with a minimum of components relatively easy to manufacture by conventional techniques, however, has increased operating reliability due to the existence of a locking position of the lock in the locked position which is obtained without the addition of any additional parts.

Claims (15)

1. A safety belt buckle particularly for a land-type automotive vehicle and intended to join a strap to an anchorage point and which consists in particular of a latch (10) and of a keeper comprising inter alia a base (20) and, carried by this latter, a lock bolt (30), an ejector guide (40), an actuating button (50) and, if necessary, a protective covering (60), in which this base (20) defines a channel (200) intended to receive at least partially the latch (10), this lock bolt (30) being mounted on this base (20) by means of an articulation (230) which allows it to move in practice only by pivoting so as to be movable between at least two positions towards which it is elastically biased, a first releasing position where the latch (10) is unlocked and a second retaining position where the latch (10) is locked on the keeper by the lock bolt (30), this ejector guide (40) having a seat (400) intended to receive the latch (10) at least partially and being mounted on this base (20) so as to be displaceable there in translation such that it is movable between a rest position towards which it is normally elastically biased and which it occupies when the lock (30) is in its first position and a set position which it occupies when the lock bolt (30) is not in its first position, this actuating button (50) being mounted on this base (20) so as to be displaceable there in translation such that it is normally elastically biased and an active position in which it causes the lock bolt (30) to pass into its first position, in which belt the lock bolt (30) is deformable elastically towards a third permanently locked position in which it is secured directly to the base (20) when it is occupying its second position, the locked buckle being subject to a force which seeks to open it and which is greater than a given value, characterised in that operating and locking means (70) associate the said actuating button (50) and this lock bolt (30) and this base (20) so that opening of the buckle is possible only when this force does not exceed the said given value and in that the operating and locking means (70) comprise at least one cam (75) carried by the actuating button (50) and cooperating with at least one counter-cam (13) on the lock bolt (30) to cause it to move towards its first position and at least one permanent-locking notch (72) formed on the base (20) and cooperating with an edge (21) of the lock bolt (30) in order to determine the third position of this latter.

2. A buckle according to Claim 1, characterised in that the lock bolt (30) has the configuration of a plate on two of the sides of which there are formed flanges (302) where these edges (71) and counter-cams (73) are located.

3. A buckle according to Claim 2, characterised in that the lock bolt (30) comprises, orientated towards the same lace of the plate as the flanges (302), a nose (301) intended to cooperate with the latch (10) in order to lock it and a base piece (320) intended to receive the elastic biasing force.

4. A buckle according to claim 3, characterised in that the elastic biasing of the lock bolt (30) and that of the ejector guide (40) are provided by a single spring (460).

5. A buckle according to any one of Claims 1 to 4, characterised in that the elastic biasing of the actuating button (50) towards its inactive position is provided by a spring (540) which bears on the protective covering (60).

6. A buckle according to any one of Claims 1 to 4, characterised in that the elastic biasing of the actuating button (50) towards its inactive position is provided by a spring (540) which bears on the lock bolt (30).

7. A buckle according to claim 6 in so far as it is taken in association with any one of Claims 3 or 4, characterised in that the lock bolt (30) comprises, orientated on the opposite side of this face of the plate, a projecting part (320) on which the spring (540) rests.

8. A buckle according to any one of Claims 1 to 7, characterised in that the articulation (230) comprises trunnions (310) located on the lock bolt (30) and L-shaped bearing points (231) formed in the base (20).

9. A burkle according to any one of Claims 1 to 8, characterised in that it comprises a buckle closure detector (80) housed in the protective covering (60).

10. A buckle according to Claim 9, characterised in that the detector (80) comprises a switch (800) the tripping member (801) of which is actuated by the lock bolt (30).

11. A buckle according to claim 9 in so far is it is taken in association with Claim 3 and the subsequent Claims, characterised in that the tripping member (801) is located in the trajectory of one of the flanges (302) of the lock bolt (30) when this latter is displaced from one of its positions to the other.

12. A buckle according to any one of Claims 1 to 11, characterised in that it comprises an illumination device (90) housed in the protective covering (60).

13. A buckle according to any one of Claims 9 to 12, characterised in that the detector (80) and the illumination device (90) are mounted on a common support (89) fixed on the base (20).

14. A buckle according to any one of Claims 12 or 13, characterised in that the illumination device (90) is disposed in such a way as to illuminate at least the channel (200) in the latch (10).

15. A buckle according to any one of claims 2 to 14, characterised in that the plate has two legs (340) and in that the elastic deformation of the lock bolt occurs at the level of these legs (340) and/or of this nose (301).

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