EP0345113B1 - Buckle for a safety belt - 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 is known, motor vehicles, in particular land vehicles, are fitted with seat belts which must meet stringent specifications, 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. Under 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. Obtaining this is tricky, because in such a situation the belt tension is around 50 daN to around 60 daN, and we must be able to open the buckle by exerting a force of around 25 daN. 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 locking interlock is, for example, described in French patent application 2,590,134.

This document describes different variants of seat belt buckles that lock. All the embodiments which are exposed meet the standards but their realization is somewhat complex. If such a complex construction does not jeopardize the reliability of these loops, it is however detrimental to relatively low manufacturing and assembly costs. In addition, these loops suffer from a relative lack of precision during the phase of introduction of the bolt into the keeper of the loop.

Another state of the art is illustrated by document FR-A-2 338 519. However, this document which aims to make visible and accessible the button for actuating a buckle for a seat belt with locking lock is of a structure such that the actuating button is pivotally mounted and that the locking bolt-shaped lock is integral with this button and plays only and only this role of locking.

The object of the invention is to produce a buckle for a seat belt, in particular for motor vehicles, for example land vehicles with locking interlock which, while offering the advantages of the buckle which has just been mentioned, does not have the advantages thereof. especially economic disadvantages.

The subject of the invention is a buckle for a seat belt, in particular for land motor vehicles, intended to join a strap to an anchor point and which is composed, in particular, of a bolt and a keeper which comprises, inter alia, a base and, carried by the latter, an ejector guide lock, an actuation button and, preferably, a protective casing.

This loop according to the invention is of a type similar to that set out in document FR-A-2 338 519 of which what it discloses and which is necessary for the invention is indicated in the preamble to the main claim, and is remarkable for the distinctive features which stand out in particular from the characterizing part thereof.

• . la Fig.1 est une vue perspective éclatée d'un mode de réalisation d'une boucle de ceinture de sécurité selon l'invention ;
• . les Fig.2A, 2B et 2C sont des coupes longitudinales schématiques de la boucle selon la Fig.1 assemblée illustrant différentes phases de son fonctionnement ;
• . les Fig.3A, 3B, 3C et 3D sont des vues de détail schématiques du système d'insertion et d'emprisonnement des moyens de la boucle selon l'invention ;
• . les Fig.4A et 4B sont des vues partielles schématiques de détail illustrant la boucle selon l'invention dans deux phases différentes de son fonctionnement ;
• . la Fig.5 est une vue perspective éclatée d'un autre mode de réalisation d'une boucle selon l'invention ;
• . les Fig.6A et 6B sont des vues partielles schématiques de détail, en coupe longitudinale, du mode de réalisation de la Fig.5 ;
• . la Fig.7 est une vue partielle de détail d'un mode de réalisation d'une boucle selon l'invention équipée de son détecteur et de son dispositif d'éclairage ;
• . la Fig.8 est une vue perspective cavalière d'une variante d'exécution de l'embase de la gâche d'une boucle pour ceinture de sécurité selon l'invention.

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.2A, 2B and 2C are schematic longitudinal sections of the loop according to Fig.1 assembly illustrating different phases of its operation;
• . Fig.3A, 3B, 3C and 3D are schematic detail views of the insertion system and imprisonment of the means of the loop according to the invention;
• . Fig.4A and 4B are partial schematic detail views illustrating the loop according to the invention in two different phases of its operation;
• . Fig.5 is an exploded perspective view of another embodiment of a loop according to the invention;
• . Fig.6A and 6B are schematic partial views of detail, in longitudinal section, of the embodiment of Fig.5;
• . Fig.7 is a partial detail view of an embodiment of a loop according to the invention equipped with its detector and its lighting device;
• . Fig.8 is a perspective view of an alternative embodiment of the base of the keeper of a buckle for a seat belt according to the invention.

As seat belt buckles are well known in the art, in particular for their application to land motor vehicles, we will describe hereinafter only that which relates directly or indirectly to the invention. For the rest, the specialist in the technique considered will draw on the conventional current solutions at his disposal to deal with the specific problems with which he is confronted.

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

Referring in particular to FIG. 1, it can be seen there that a seat belt buckle according to the invention comprises a bolt 10 intended to be locked on a keeper when the buckle is closed. This keeper includes a base 20, an ejector guide lock 30, an actuating button 50, possibly a protective cover 60, a securing link 70 intended to anchor the keeper to a shell or structure of a vehicle not shown and, if necessary, a locking detector 80 and a lighting device 90. This loop also includes means 40 for locking the ejector guide lock in the locked position, for inserting and locking the bolt and for guiding the lock. ejector guide.

For the convenience of the description, each of the constituents of the embodiment of a loop according to the invention will be described successively before indicating its operation.

The bolt 10 comprises a body 101 which continues with an extension 102. The body 101 is pierced with a passage 103 intended to receive the strand of a seat belt strap, not shown, and the extension 102 is pierced with a cutout 104 by which the bolt is kept locked on the keeper when the loop is closed.

The base 20 has the configuration of a U-shaped part. As can be seen, the bottom 201 is bordered by two practically parallel sides 202. On the bottom 201 is located a spout 210 which has an inclined face 211 and which ends in a slice 212. This spout results, for example, from the cutting of an opening 209 in the bottom 201. This bottom is also pierced with a hole 214 to which we will return. Each of the flanks 202 is pierced with an opening 204 and has an ear 220 and a flap 221. Each of the flanks is also provided with a cam 410 and crossed by a light 430 in broken line which has a flat 431 and a ramp 432 A channel 200 intended to receive the extension 102 of the bolt is thus delimited by the bottom 201, the face 211, part of the two sides 202 and the cam 410.

The ejector guide lock 30 is in the manner of a block 301, approximately parallelepipedic, on two of the opposite faces of which are placed a housing 300 and a stud 310. The housing 300 has a bevel 301 at its entry and is delimited by a ceiling 302, a partition 303 and a floor 304. This housing is intended to receive the extension 102 of the bolt 10. On two opposite cheeks 320 of the block 301 are arranged cams 420 and wings 440 which, as illustrated, are consist of a flat 441 and a slope 442 at least.

The actuation button 50 comprises a front 501 in which is formed a mouth 510 intended to allow passage to the extension 102 of the bolt. This facade 501 is associated with lateral walls 502 which are extended by fingers 520 terminated by a shoulder 521. Each of the fingers 520 and walls 502 are hollowed out with a groove 503.

The protective envelope 60 consists, for example, of a housing 600 which has a relatively rigid and flexible lip 602. This housing is for example made of a single piece or of two half-shells joined to one another by any suitable technique, for example by interlocking, embedding, welding, gluing, or the like.

The joining link 70 comprises a rod 700, one end of which is provided with a stud 702 and two protrusions 703. A hole 701 pierces this rod and is intended to be matched with the hole 214 in the bottom 201 of the base 20 in order to receive a rivet, eyelet or the like 612. This rivet or the like makes it possible to join the striker and the anchoring point.

A spring 309 is intended to be threaded simultaneously on the stud 310 of the ejector guide lock 30 and on the stud 702 of the securing link 70.

The means 40 of the loop according to the invention consist of a locking arrangement which comprises the cam 410 and the cam follower 420, of a guide device which comprises the slots 430 and the wings 440 as well as a system insertion-imprisonment which includes the housing 300 with its bevel 301.

Preferably, the body 101 and the extension 102 of the bolt are metallic and, if necessary at least for the body, coated with plastic material as is conventional and illustrated. The base 20 is preferably metallic and obtained by cutting, stamping and folding a suitable sheet metal, making "semi-punctured" there if necessary. The ejector guide lock 30 and the actuation button 50, as well as the protective envelope 60, are preferably obtained by molding of suitable plastics. The connection 70 is preferably made of metal.

To proceed with the assembly of this embodiment of a seat belt buckle according to the invention, the procedure will be as indicated below, for example.

The rod 700 is approached from the base 20 and its protrusions 703 are engaged in the openings 204, then these two parts are assembled which are kept together using the rivet or eyelet 612 introduced through holes 214 and 701 There is then presented, suitably oriented, the ejector guide lock 30 so that its wings 440 are perpendicular to the slots 430 in which they are engaged. This done, the spring 309 is placed on each of the pins 310 and 701 which hold it in place. The actuation button 50 is then presented so that the grooves 503 of its fingers 520 are facing the ears 220. The button is then made to slide on the base so that its fingers 520 cross the flaps 221 in deviating relatively from each other by elastic deformation facilitated by suitable chamfers until the shoulders 521 escape the flaps 221 and return in place behind them. In this way, the actuation button can slide in translation relative to the base without being able to disengage therefrom. If necessary, the assembly is completed by sliding the housing 600 on the rod 700 until the lip 602 comes to hang and lock on the edge of the base by elastic deformation. The result of all this is clearly illustrated in Figs. 2A, 2B and 2C.

The operation of this embodiment of the loop according to the invention is as follows. We will refer more particularly to Figs. 2, 3 and 4.

It will first be observed that, as is particularly clear from the illustrations in the figures of the drawing, the channel 200 and the housing 300 are inclined relatively to each other and oriented so that the channel 200 has a ascending obliquity towards the housing 300. By virtue of its mounting on the base thanks to its wings 440 engaged in the slots 430, it can be seen that the ejector guide lock 30 is movably mounted on the base 20 so as to be able to be move by describing a broken line trajectory between a first retaining position towards which it is normally elastically urged by the spring 309 and a second position towards which it is momentarily pushed back when the bolt is introduced into the keeper for its locking.

Similarly, it can be seen that, thanks to the mutual engagement of the grooves 503 and the ears 220 of the actuation button and of the base respectively, the actuation button 50 is mounted movable in translation on the base 20 between a inactive position towards which it is elastically biased indirectly by the ejector guide lock 30, and that it occupies when the latter is in its first position, and an active position for passing the ejector guide lock 30 from its first to its second position in order to release the bolt from the striker when manually pressing on the front of the button. actuation to push it into the protective casing.

To close the loop according to the invention, as seen in particular in FIG. 2A, the extension 102 of the bolt 10 is introduced into the mouth 510 of the actuation button 50 and it is made to travel in the channel 200 inclined up to 'so that its free upstream edge meets the bevel 301 of the housing 300. By doing this and continuing the effort illustrated by the arrow in Fig.2A, the ejector guide lock 30 is progressively pushed back which compresses the spring 309. Due to the broken line configuration of the lights 430, it is understood that the ejector guide lock 30 first moves back while remaining in its plane, practically parallel to the housing, then then rises gradually. Due to its progressive elevation, the housing 300 of the ejector guide lock 30 is then placed in the extension of the channel 200 and the upstream edge of the bolt can engage in the housing 300. This insertion of the bolt into the housing is facilitated by the configuration of the bevel 301 to which we will return.

This being the case, it can be seen that the cutout 104 of the extension 102 of the bolt 10 is now now above the beak 210. The width of this cutout 104 is a little greater than the width of the beak 210 so as to be able to freely enter into it. The extension 102 of the bolt 10 having fully engaged in the housing 300 of the ejector guide lock 30, if one stops pushing the bolt 10 in the following strike the direction of the arrow, the spring 309 which was compressed during this phase gradually relaxes by pushing the ejector guide lock 30 as illustrated in FIG. 2B. During this phase of operation, the ejector guide lock 30 returns to its initial position, its first retaining position (FIG. 2C), by lowering itself to resume its original level by driving the bolt with it. Returning to its first position, the ejector guide lock 30 pushes the bolt towards the spout and the extension of the bolt hangs on the edge 212 of the spout. In the final locking phase, the loop according to the invention is in the configuration illustrated in FIG. 2C.

When the loop assumes the position in which it is illustrated in FIG. 2C, it is understood that the cam 410 and cam follower 420 have come into contact with one another and ensure the jamming of the ejector guide lock 30 in the position where it is illustrated. It can therefore be seen that the buckle is then in a situation such that the bolt locked directly on the base is also doomed in this situation, hence very great security when the buckle is closed. This very high security is further increased due to the direct junction which exists between the connection 70 and the base 20 resulting from the reciprocal engagement of the protrusions 703 and the openings 204. The rivet, eyelet or the like 610 undergoes a force. attenuated shear and is there essentially to maintain or join together the rod 700 and the base 20.

To unlock the loop, simply press the actuation button 50 to press it. The kinematics of the loop is then that which is schematically illustrated in FIGS. 4A and 4B. Fig. 4A corresponds to the position of the loop in the locked and locked position. When the actuation button 50 is pressed, it rests on the ejector guide lock 30 which it pushes back (cf. FIG. 2C). Backing up, the ejector guide lock 30 first slides in its plane, then rises. By doing this, the extension 102 of the bolt being retained in the housing 300, the ejector guide lock 30 carries with it the extension 102 which then emerges from the spout 210. When the underside of the bolt is at a level higher than that of the upper face of the beak, the slightest force exerted on the bolt, for example via the strand of the strap, is sufficient to release the bolt from the housing. The ejector guide lock 30 is then pushed back by its spring 309 which relaxes, the actuation button 50 having been released. By doing this, the ejector guide lock 30 then completely ejects the bolt from the strike if it had not already been removed.

Referring to the various illustrations in FIGS. 3A, 3B, 3C and 3D, it can be seen that the bevel 301 can have various configurations. In Fig.3A, it looks like a cylinder section with a relatively large radius. In Fig. 3B, this radius is the same, but the bevel is more inclined. In Fig.3C, this is a flat chamfer, and in Fig.3D, a combination of a flat chamfer and a cylinder section. It is easily understood that the choice of precise configurations given to this bevel 301 is a function of the nature and the surface conditions of the parts of the ejector guide lock 30 and of the bolt 10 intended to come into contact and to cooperate. This bevel must be able to guide the extension of the bolt so that it engages without fail and without significant effort in the housing.

Fig.5 is an exploded view, similar to that of Fig.1, of another alternative embodiment of the loop according to the invention where the actuating button 50 and the ejector guide lock 30 are made of in one piece, for example in molded plastic. As can be seen, the ejector guide lock 30 and the actuation button 50 are joined by a web 530 bordered at each of its ends by grooves 531 and 532 which forming therein zones of weakness allow a certain flexibility which allows therefore making the movements of the button and the lock relatively independent, the actuation button moving in a rectilinear translation, while the lock moves along a broken line path.

In Fig.7, there is illustrated the locking detector 80 and the lighting device 90 which are mounted on a common support 89 which is fixed for example by snap-fastening on the base 20 as is conventional and for this not detailed. The detector 80 is for example constituted by a miniature switch 800, the operating member 801 of which is placed on the path of the bolt to detect the presence of the latter in the locked position. This miniature switch is associated with conventional electrical circuits so as to activate a light and / or acoustic signal to indicate that a passenger present in the vehicle has not locked their seat belt.

The lighting device 90 is for example made up of an electroluminescent diode or of a miniature bulb. This device is intended to illuminate at least the channel for introducing the bolt into the keeper in order to facilitate the locking of the belt. This device is associated with a conventional electrical circuit of any known type so that the bulb lights up when the doors are opened, for example simultaneously with the overhead light, or when the lighting of the vehicle for example parking lights or low beam or high beam.

According to another alternative embodiment illustrated in Fig.8, the base 20 is somewhat modified. In this embodiment, bosses 203 have been formed therein, for example "semi-punctured", on each of the sides 202 so as to use them to help delimit the channel 200. In this case, the channel is delimited by the bottom of the base, the face of the spout, part of the two sides and the bosses in question.

For the rest, the operation is the same. Here again a single spring ensures the elastic stresses of the ejector guide lock and of the actuation button.

According to an embodiment not shown, the housing 300 of the ejector guide lock 30 is such that its floor 304 is no longer in one piece but on the contrary consists of a flexible central sole bordered on either side by rigid lateral tabs. The level of the floor is somewhat higher than that of the lateral tabs so as to be able to exert a certain constraint to momentarily retain the bolt in its housing as in the previous embodiment so that it "follows" the ejector guide lock during the opening of the loop when the actuation button is pressed to depress it.

We understand all the interest and all the advantages of the buckle according to the invention which, with a minimum number minimorum of relatively simple configuration pieces and relatively easy to manufacture in particular in series, ensures the locking of the bolt when the latter is locked .

Claims (18)

1. A buckle for a safety belt, in particular for automobile land vehicles, adapted to connect a belt to an anchoring point and which comprises, inter alia, a bolt (10) and a clasp which comprises in particular a support (20) which bounds a channel (200) at least partially receiving the bolt (10) and which is provided with a nose (210) on which the bolt (10) may be directly hooked when it is locked in the clasp and, borne by this support, a lock (30) which is mounted to move on the support (20) between a first retaining position towards which it is normally elastically urged and a second position towards which it is momentarily pushed during the insertion of the bolt (10) into the clasp for its locking and which, when it moves from its first to its second position, describes a trajectory shown in broken lines which is initially approximately parallel to the support (20) then inclined with respect thereto and vice versa, means (40) for dead-locking the lock (30) in its first position and guiding it over its trajectory shown in broken lines when it moves from one to the other of its two positions and an actuating button (50) mounted to move on the support (20) between an inactive position towards which it is normally elastically urged and which it occupies when the lock (30) is in its first position and an active position where the lock (30) is caused to move from its first to its second position in order to release the bolt (10) from the clasp, which buckle is characterized in that the actuating button is mounted to move in translation and in that the lock (30) which as an ejector guide bounds a housing (300) at least partially receiving the bolt (10) and is provided with a system (301, 302, 303, 304) for the insertion and engagement of the bolt (10) in the housing (300) and in that the channel (200) and the housing (300) are inclined with respect to one another and oriented such that the inclination of the channel (200) rises in the direction of the housing (300).
2. A buckle as claimed in claim 1, characterized in that this system of insertion and engagement (301, 302, 303, 304) is formed by a bevel (301) disposed at the inlet of the housing (300), the lock ejector guide (30) and the ceiling (302), partition (303) and floor (304) bounding this housing (300).
3. A buckle as claimed in claim 1 or 2, characterized in that these means (40) comprise a dead-locking arrangement (410-420) and in that this dead-locking arrangement (410-420) is formed by at least one cam (410) on the support and at least one counter-cam (420) on the lock ejector guide (30) which cooperate by wedging when the lock ejector guide (30) is in its first position.
4. A buckle as claimed in any one of claims 1 to 3, characterized in that these means (40) comprise a guide device (430-440).
5. A buckle as claimed in claim 4, characterized in that this device (430-440) is formed by at least one port (430) provided in the support (20) and in which at least one flange (440) of the lock ejector guide (30) is engaged.
6. A buckle as claimed in claim 5, characterized in that the port (430) comprises a flat portion (431) in practice parallel with the housing (300) and a ramp (432) inclined with respect to the flat portion (431).
7. A buckle as claimed in any one of claims 3 to 6, characterized in that the channel (200) is bounded by a portion of the two opposite sides of the support (20), the surface (211) of the nose (210) and the cams (410).
8. A buckle as claimed in any one of claims 1 to 6, characterized in that the channel (200) is bounded by a portion of the two opposite sides (202) of the support (20), bosses (203) provided on the sides (202) and the surface (211) of the nose (210).
9. A buckle as claimed in any one of claims 2 to 8, characterized in that the floor (304) comprises a flexible median sole bordered by rigid lateral tongues disposed at a lower level than the sole.
10. A buckle as claimed in any one of claims 1 to 9, characterized in that the elastic stressing of the lock ejector guide (30) and the button (50) is ensured by a single spring (309).
11. A buckle as claimed in any one of claims 1 to 10, characterized in that the lock ejector guide (30) and the button (50) are rigid with one another.
12. A buckle as claimed in claim 11, characterized in that the lock ejector guide (30) and the button (50) are made in one piece.
13. A buckle as claimed in claim 12, characterized in that the lock ejector guide (30) and the button (50) are connected to one another by a web (530) bounded by two grooves (531, 532) allowing local bending.
14. A buckle as claimed in any one of claims 1 to 13, characterized in that it comprises a locking detector (80).
15. A buckle as claimed in claim 14, characterized in that the locking detector (80) comprises a miniature switch (800) whose operating member (801) is disposed along the trajectory of the bolt (10).
16. A buckle as claimed in any one of claims 1 to 15, characterized in that it comprises a lighting device (90).
17. A buckle as claimed in any one of claims 14 to 16, characterized in that the detector (80) and the lighting device (90) are mounted on a common support (89).
18. A buckle as claimed in any one of claims 1 to 17, characterized in that the clasp is housed at least partially in a protective casing (60).

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