EP0489950B1 - Lock for automobile safety belt - Google Patents

Description

The invention relates to a buckle for seat belt systems in vehicles which are provided with a rear tensioning device engaging the buckle, with a load-bearing housing in which an insertion path for a tongue is formed, a latch engaging with the tongue which is between a first position in which the tongue is blocked in the lock, and a second position, in which the tongue is released from the lock, is movable, a release button which is spring-loaded into a rest position and by its actuation in the direction of the insertion movement of the tongue, which with the Back tightening direction coincides until the latch is moved into the second position in a release position, and a mass body which at the end of a back tightening stroke compensates for the inertia of the release button, as is known from WO-A-9 010 397.

Locksmiths for seat belt systems are known in numerous designs. A design has proven itself in which an insertion path for the tongue is formed in the load-bearing housing of the lock, and a latch which is guided on the housing so as to be displaceable transversely to the insertion path or cooperates with a latching opening of the tongue interacts. A locking member which is displaceably guided in the housing parallel to the insertion path holds the bolt in its locking position as long as a release button which is likewise displaceably guided in the housing parallel to the insertion path is in its rest position. This release button is coupled to the locking member to move this when actuated into a release position in which the bolt comes out of the latching opening of the tongue.

The use of such a lock in seat belt systems with a back tensioning device is unproblematic if the back tensioning force is effective, for example, on the belt retractor. Back tensioning devices have also been proposed which take effect between the lock and its attachment point on the vehicle body or a vehicle seat. Such tightening devices shorten the distance between the fastening point of the lock and the lock itself by a few cm, for example 10 cm.

The force required for back tensioning can be generated mechanically by means of a strongly dimensioned spring or pyrotechnically. If the back tension force is of sufficient magnitude, especially when using pyrotechnic back tension drives, in certain cases an automatic opening at the end of the back tension path can occur when using a lock of the type specified at the beginning.

The automatic opening of the lock at the end of the back tightening movement is attributed to the inertia of the release button and possibly components attacking it, since the release button at the end of the back tightening movement endeavors to continue its movement in the back tightening direction which corresponds to the actuation direction of the release button. It was already proposed to prevent this movement of the release button under the influence of inertial forces by using pivotable balancing masses, mass bodies or pawls.

If the lock is provided with such a pawl or balancing mass, which becomes active at the end of the backward movement due to inertia to prevent the movement of the release button in the actuating direction, then this pawl or balancing mass is a component that during the life of the Castle never becomes active. Only during a back tightening process, which may only occur after 10 years of use of the lock, should the pawl or balancing mass be shifted from a rest position through its inertia to a locked position. In its rest position, it is usually held by a spring. It cannot now be ruled out that impairment of the functionality of the pawl or balancing mass will occur in the course of the long period of use of the lock. For example, a pawl can be prevented from getting out of its rest position into its locked position by dirt or penetration of foreign bodies.

Based on these findings, the invention provides a lock for seat belt systems in vehicles, which ensures a forced movement of the mass body each time the release button is pressed. This forced movement of the mass body each time the release button is pressed, its freedom of movement is guaranteed even over long periods of 10 or more years.

The lock according to the invention for seat belt systems in vehicles is characterized in that at least one first toothing element is formed on the release button or on a part which is at least non-positively connected to it, and that a second toothing element is formed on the mass body which is movably mounted relative to the housing, that the first toothing element and the second gear element directly or via an interposed third tooth element permanently in meshing engagement with one another, that the direction of the movement transfer caused by the meshing of the toothing elements between the release button and mass body is determined such that the inertia of the mass body opposes the movement of the release button in the backward direction, and that the mass body underneath Taking into account the transmission ratio between the toothing elements is dimensioned such that the inhibiting force generated by it, which opposes the movement of the release button in the back tightening direction, is sufficient to prevent the release button from moving into its release position at the end of the back tightening movement of the lock.

The lock according to the invention is characterized by an extremely high level of functional reliability in a back tightening process due to the regular forced movement of the mass body each time the release button is pressed.

Advantageous developments of the invention are specified in the subclaims.

Fig. 1

einen schematischen Längsschnitt eines Schlosses für Sicherheitsgurte in Fahrzeugen, bei dem die Erfindung anwendbar ist;

Fig. 2

eine zum Teil in Perspektive gezeigte schematische Seitenansicht des in Fig. 1 gezeigten Schlosses;

Fig. 3

eine Skizze, die das Wirkungsprinzip einer ersten Ausführungsform des erfindungsgemäßen Schlosses veranschaulicht;

Fig. 4

eine zum Teil weggebrochen gezeigte Perspektivansicht einer Ausführungsform, die auf dem in Fig. 3 gezeigten Prinzip beruht;

Fig. 5

eine Skizze zur Veranschaulichung des Wirkungsprinzips einer weiteren Ausführungsform der Erfindung;

Fig. 6

eine Teil-Perspektivansicht einer Ausführungsform, die auf dem in Fig. 5 gezeigten Prinzip beruht;

Fig. 7

einen schematischen Längsschnitt einer weiteren Ausführungsform zur Veranschaulichung des dieser zugrunde liegenden Prinzips;

Fig. 8

eine perspektivische Schnittansicht der in Fig. 7 gezeigten Ausführungsform;

Fig. 9

eine Skizze, die eine Abwandlung der Ausführungsform nach den Fig. 7 und 8 zeigt;

Fig. 10

eine perspektivische Schnittansicht der in Fig. 9 gezeigten Ausführungsform;

Fig. 11

eine Skizze zur Veranschaulichung des Wirkungsprinzips einer weiteren Ausführungsform;

Fig. 12, 13 und 14

Skizzen zur Veranschaulichung des Wirkungsprinzips weiterer Ausführungsformen;

Fig. 15

eine Perspektiv-Teilansicht einer Ausführungsform, die auf dem in Fig. 14 gezeigten Prinzip beruht;

Fig. 16

eine Skizze, die eine Abwandlung der Ausführungsform nach den Fig. 14 und 15 zeigt; und

Fig. 17

eine Teil-Perspektivansicht der Ausführungsform nach Fig. 16.

Several embodiments of the invention will now be described in more detail with reference to the drawing. The drawing shows:

Fig. 1

a schematic longitudinal section of a lock for seat belts in vehicles, in which the invention is applicable;

Fig. 2

a schematic side view, partly in perspective, of the lock shown in FIG. 1;

Fig. 3

a sketch illustrating the principle of operation of a first embodiment of the lock according to the invention;

Fig. 4

a partially broken perspective view of an embodiment based on the principle shown in Fig. 3;

Fig. 5

a sketch to illustrate the principle of action of a further embodiment of the invention;

Fig. 6

a partial perspective view of an embodiment based on the principle shown in Fig. 5;

Fig. 7

a schematic longitudinal section of a further embodiment to illustrate the principle on which this is based;

Fig. 8

a perspective sectional view of the embodiment shown in Fig. 7;

Fig. 9

a sketch showing a modification of the embodiment of FIGS. 7 and 8;

Fig. 10

a sectional perspective view of the embodiment shown in Fig. 9;

Fig. 11

a sketch to illustrate the principle of action of a further embodiment;

12, 13 and 14

Sketches to illustrate the principle of action of further embodiments;

Fig. 15

a partial perspective view of an embodiment based on the principle shown in Fig. 14;

Fig. 16

a sketch showing a modification of the embodiment of FIGS. 14 and 15; and

Fig. 17

16 shows a partial perspective view of the embodiment according to FIG. 16.

In the embodiment of a lock for seat belts in vehicles shown in FIGS. 1 and 2, a load-bearing housing 10 is surrounded by a cover shell 12 made of plastic. The housing 10 is connected by a rivet 14 to a fitting part 16, on which a back tensioning device (not shown) engages in a known manner. When this back tensioning device is activated, the lock is moved in the direction of arrow F by a few cm, for example 10 cm, towards the vehicle floor. The load-bearing housing 10 is made from a generally U-shaped metal plate. An insertion path for a tongue 18 of the seat belt system is formed between the two legs of the housing 10. The webbing 20 is guided through a slot 22 of the tongue 18.

A bolt 26 loaded by a compression spring 24 is displaceably guided transversely to the insertion path of the lock. In its position shown in FIG. 1, it crosses aligned openings of the housing 10 and the tongue 18. Between the inside of the cover shell 12 and the housing 10, a release button 28 is slidably guided. This release button 28 is provided with a recess for the passage of the bolt 26. The release button 28 is biased by at least one compression spring 30 into its unactuated position shown in FIG. 1; 2 such compression springs can be seen.

In the embodiment of the lock shown in FIGS. 3 and 4, a toothing element in the form of a toothed strip 40 is molded onto the release button 28. A lever 42 is pivotally mounted on the inside of the housing shell 12. This lever 42 forms a mass body with the center of gravity S, which is located at a distance from the pivot bearing of the lever 42. A pinion segment 44 is integrally formed on the lever 42 concentrically with the pivot axis. This pinion segment 44 is permanently in meshing engagement with the toothed rack 40. Each time the release button 28 is actuated, the lever 42 therefore turns in the opposite direction Direction of movement of the release button 28 pivoted. If, at the end of a back tightening process, in which the lock is shifted towards the vehicle floor by the back tightening device in the direction of arrow F in FIG. 1, the release button 28 strives to continue the movement in the direction of arrow F due to its inertia, namely in one direction, which corresponds to its direction of actuation for opening the lock, the inertia of the lever 42 counteracts it, since, because of the direct meshing engagement between the toothed rack 40 and the pinion segment 44, the release button 28 can only move in the direction of arrow F if the lever 42 is pivoted in the direction of arrow A in Fig. 3. By dimensioning the lever 42 and suitably arranging its center of gravity S relative to its pivot axis, complete compensation for the inertia of the release button 28 can be achieved in a simple manner. Since the lever 42 is forced to pivot each time the release button 28 is actuated, its smooth operation is ensured even after the lock has been in use for a long time. A stiffness of the lever 42 caused, for example, by dirt or penetrated foreign bodies would have the consequence that the compensation of the inertia of the release button 28 would be incomplete; Because of the extremely high delays that can occur at the end of a backstroke stroke at the lock, an automatic opening would then be feared by moving the release button in the direction of actuation. The principle underlying the invention of causing a forced movement of the mass body acting as a compensating mass each time the release button is actuated, the compensation effect remains unaffected even after a long period of use of 10 years or more.

In the embodiment according to FIGS. 5 and 6, a rack 40 is in turn arranged on the release button 28. However, the toothed rack 40 is in meshing engagement with an externally toothed disk 50, which at least approximately in its center of gravity, which corresponds to its center, by means of a bearing pin 52 on the inside of the cover shell 12 (in FIGS. 5 and 6 not shown) is rotatably mounted. A bore 54 in the body of the disk 50 compensates for imbalances which are caused on the outer circumference of the disk 50 in the region of its external toothing 56 by the mass left out there.

Each time the release button 28 is actuated, the disc 50 is rotated due to the continuous meshing between its teeth 56 and the toothed rack 40. Since the disc 50 is mounted smoothly, the actuation of the release button 28 is in no way hindered by it. However, if, especially at the end of a backstroke stroke, the release button 28 strives to continue its movement due to its inertia, the direction of which corresponds to its normal direction of actuation, then the inertia of the disk 50 opposes this movement. Due to its inertia, the disk 50 tries to maintain its rotational position in space. In order to accelerate the disk 50 to a rotational speed which corresponds to the speed of the downward movement of the release button 28 at the end of the back tightening stroke, a high energy would have to be applied due to the conservation of the angular momentum. The disk 50 can easily be dimensioned so that the release button 28 is never able to apply this energy. A particular advantage of the embodiment shown in FIGS. 5 and 6 is that the disk 50, since it is supported in its center of gravity, exerts an inhibiting force on the release button 28 that is independent of its rotational position and can have a relatively low mass overall, since the angular momentum is quadratic in relation to the radius on which the mass elements of the disk lie.

In the embodiment according to FIGS. 7 and 8, two pinions 60, 62 are rotatably mounted on the release button 28. These pinions 60, 62 are arranged symmetrically to the longitudinal axis of the lock. Each pinion 60, 62 is in meshing engagement with an associated toothed rack 64, 66, which is integrally formed on the inside of the cover shell 12, and at the same time with a toothing 70, 71 on one leg of a U-shaped mass body 72. The Pinions 60, 62 are arranged between the legs of the mass body 72. The mass body 72 is mounted displaceably relative to the load-bearing housing 10 of the lock in the actuation direction of the release button 28. The release button 28 is loaded into its rest position by two compression springs 30.

Due to the permanent meshing engagement between the pinions 60, 62 and the toothed strips 64, 66 on the one hand and between these pinions and the toothings 70, 71 on the other hand, the pinions 60, 62 run in the direction of arrow B in FIG. 8 each time the release button 28 is actuated the toothed strips 64, 66 and on the toothing 70, 71 and are moved down with the release button. The mass body 72 remains at rest during this process. It therefore does not in any way impair the smooth operation of the release button 28.

If, however, at the end of a back tightening stroke, the mass body 72 and the release button 28, due to their inertia, the movement in the back tightening direction indicated by the arrow F is sought, while the load-bearing housing 10 with the cover shell 12 is suddenly braked, the toothings 70, 71 practice on the circumference of the pinions 60, 62, a torque which tends to rotate these pinions in a sense opposite to the direction of rotation which occurs when these pinions run on the toothed strips 64, 66 when the release button is moved in the actuation direction B. Thus, while the mass body 72, through its meshing engagement with the pinions 60, 62, strives to run them counter to the actuating direction B on the toothed racks 64, 66, in FIG. 8 upwards, the release button 28 strives because of its inertia, which Take pinion 60, 62 with them in the direction of actuation B via their bearing pins. The inertia forces exerted by the release button 28 on the one hand and by the mass body 72 on the other hand therefore counteract one another, so that neither the release button 28 nor the mass body 72 is displaced relative to the housing or to the cover shell 12. An unintentional Opening the lock at the end of the back tension stroke is therefore excluded.

The embodiment shown in FIGS. 7 and 8 is characterized by a high mechanical strength due to its symmetrical structure. The space required for accommodating the pinion and the mass body is small, especially since the mass body 72, although it is movable in the longitudinal direction relative to the load-bearing housing and to the cover shell, practically does not change its position relative to the housing and cover shell.

In the embodiment according to FIGS. 9 and 10, the mass body 72 is rod-shaped and arranged between the pinions 60, 62. Furthermore, the toothed strips 64, 66 are molded onto a longitudinally extending rib 76 of the cover shell 12. Otherwise, the structure and mode of operation of this embodiment correspond to those in the embodiment according to FIGS. 7 and 8.

The embodiment shown in FIG. 11 comes close to that of FIGS. 2 and 3. Deviating from this, however, the toothing element, with which the toothed strip 40 is in meshing engagement, is designed as a pinion 60 which is rotatably mounted on the inside of the cover shell. This pinion 60 is permanently meshed with the toothed rack 40 and a toothing on a rod-shaped mass body 80. The mass body 80 is slidably mounted in the longitudinal direction relative to the load-bearing housing and to the cover shell of the lock. With each movement of the release button 28 in the actuation direction B, the pinion 60 is set in rotation. Since the center of the pinion 60 is fixed to the cover of the lock, the mass body 80 must move in the opposite direction to the movement of the release button 28 when the pinion rotates. Because of the permanent meshing engagement between the pinion 60, the rack 40 and the toothing of the mass body 80, the inertial forces of the release button 28 and mass body 80 counteract each other. The inertia of the mass body 80 therefore prevents further movement of the release button 28 in the actuation direction B relative to the housing and cover shell of the lock at the end of a backstroke stroke.

The embodiments according to FIGS. 12 and 13 differ from that according to FIG. 11 in that the pinion 60 is replaced by a toothing element 82 or 84, which has two arc-shaped toothing segments 82a, 82b, which are at different distances from the pivot bearing of the toothing element 82 are located. The toothing element 82 therefore causes a translation or reduction between the movements of the release button 28 and the mass body 80 in the longitudinal direction of the lock, depending on the ratio of the distances of the toothing elements 82a, 82b from the bearing axis of the toothing element 82. In the embodiment according to FIG. 12 the movement of the release button 28 via the toothing element 82 is translated into a larger movement of the mass body 80; 13, on the other hand, the movement of the release button 28 is reduced to a smaller movement of the mass body 80. As a comparison of FIGS. 12 and 13 shows with one another, the size of the mass body can be adapted in accordance with the transmission ratio or reduction ratio.

In the embodiments according to FIGS. 14 to 17, two pinions 60, 62 are rotatably mounted on the inside of the cover shell of the lock. As in the embodiment according to FIGS. 7 and 8 or 9 and 10, the release button 28 is provided with two molded toothed racks 64, 66. The rack 64 is in mesh with the rack 62, the rack 66 with the rack 60. At the same time, the pinions 62, 60 are in meshing engagement with opposing toothings 70, 71 of a mass body 72. The mass body 72 is mounted so as to be displaceable in the longitudinal direction relative to the housing of the lock and to its cover shell. The mode of operation corresponds to that in the embodiment according to FIG. 11 and is therefore not explained again. By using two symmetrically arranged pinions 60, 62 and toothed racks 64, 66 with a likewise symmetrically formed mass body arranged between the pinions, a high mechanical strength is achieved.

In the embodiment according to FIGS. 16 and 17, the mass body 72 is not rod-shaped as in FIGS. 14 and 15, but is U-shaped, and the pinions 60, 62 are arranged between the legs of the mass body. In this embodiment too, the pinions 60, 62 are rotatably mounted on the inside of the cover shell. The principle of operation of this embodiment corresponds in principle to that of the embodiment according to FIGS. 14 and 15.

Claims (12)

1. Buckle for safety belts in vehicles which are provided with a tightening means engaging on the buckle, a loadbearing housing (10) in which an insert path for an insert tongue (18) is formed, a locking bar (26) which engages the insert tongue (18) and is movable between a first position in which the insert tongue (18) is blocked in the buckle and a second position in which the insert tongue (18) is released from the buckle, a release button (28) which is biased by spring force (30) into a rest position and by actuation of which in the direction of the insert movement (B) of the insert tongue (18), which corresponds to the tightening direction (F), into a release position the locking bar (26) is moved into the second position, and a mass body (42; 50; 72) which at the end of a tightening travel compensates the mass inertia of the release button (28), characterized in that on the release button (28) or on a member connected at least in force-locking manner thereto at least one first toothing element (40; 60, 62; 82; 84) is formed, that on the mass body (42; 50; 72) mounted movably relatively to the housing (10) a second toothing element (44; 56; 70, 71) is formed, that the first toothing element and the second toothing element are in meshing engagement with each other permanently directly or via an interposed third toothing element, that the direction of the movement transmission between release button (28) and mass body (42; 50; 72) effected by the meshing engagement of the toothing elements is so defined that the mass inertia of the mass body opposes the movement of the release button in the tightening direction, and that the mass body (42; 50; 72) taking account of the transmission ratio between the toothing elements is so dimensioned that the inhibiting force generated thereby and opposing the movement of the release button (28) in the tightening direction (F) suffices to prevent a mass-inertia-induced movement of the release button (28) into its release position at the end of the tightening movement of the buckle.
2. Buckle according to claim 1, characterized in that the first (40) and the second (44) toothing element are in direct meshing engagement with each other and the mass body (42) is formed as lever which is pivotally mounted on a housing-fixed part and comprises the second toothing element (44) as pinion or pinion segment, the centre point of which coincides with the pivot axis of the mass body (42).
3. Buckle according to claim 1, characterized in that the first toothing element (40) formed as toothed strip and the second toothing element (56) are in direct meshing engagement with each other and the mass body (50) is formed as externally toothed disc which is mounted at least approximately in its centre of gravity rotatably on a housing-fixed part.
4. Buckle according to claim 1, characterized in that the first toothing element (60, 62) formed as pinion and mounted rotatably on the release button (28) is in direct meshing engagement with the second toothing element (70, 71) formed as toothed strip and arranged on the mass body (72) and at the same time with a housing-fixed toothed strip (64, 66) and that the mass body (72) is mounted translationally displaceably relatively to the housing (10).
5. Buckle according to claim 4, characterized in that on the release button (28) two pinions (60, 62) are rotatably mounted which are both in meshing engagement with a respective toothed strip (71, 72) of the mass body (72) and at the same time with a respective housing-fixed toothed strip (64, 66).
6. Buckle according to claim 5, characterized in that the mass body (72) is made rod-shaped and is arranged between the pinions (60, 62).
7. Buckle according to claim 5, characterized in that the mass body (72) is made U-shaped and the pinions (60, 62) are arranged between the legs thereof.
8. Buckle according to claim 1, characterized in that the third toothing element (60, 62) via which the first toothing element formed as toothed strip (64, 66) and arranged on the release button (28) is in meshing engagement with the second toothing element likewise formed as toothed strip (71, 72) and arranged on the mass body (72) guided translationally displaceably relatively to the housing (10) is formed as pinion.
9. Buckle according to claim 1, characterized in that the third toothing element (82, 84) via which the first toothing element formed as toothed strip (40) and arranged on the release button (28) is in meshing engagement with the second toothing element likewise formed as toothed strip and arranged on the mass body (80) guided translationally displaceably relatively to the housing (10) is constructed as toothing element which is pivotally mounted relatively to the housing and on which two arcuate toothing sections (82a, 82b) are formed which are located at different distances from the pivot bearing of the toothing element (82) and of which the one (82b) is in meshing engagement with the toothed strip (40) of the release button (28) and the other (82a) is in meshing engagement with the toothed strip of the mass body (80).
10. Buckle according to claim 8, characterized in that the release button (28) is in meshing engagement via a respective toothed strip (64, 66) with a respective pinion (60, 62) mounted rotatably relatively to the housing (10) and the mass body (72) is also in meshing engagement via a respective toothed strip (71, 70) with a respective one of the two pinions (60, 62).
11. Buckle according to claim 10, characterized in that the mass body (72) is made rod-like and is arranged between the two pinions (60, 62).
12. Buckle according to claim 10, characterized in that the mass body (72) is made U-shaped and the pinions (60, 62) are arranged between the legs thereof.

Images