Belt buckle for a safety belt system

Abstract

A belt buckle for a safety belt system for latching a belt buckle (1) with a casing (4), and a locking mechanism (3) arranged in the casing (4), and a spring element (13) loading the latching mechanism (3) in the closing direction, and a damping element that acts against the closing direction of the lathing mechanism (3). The damping element is formed by a soft layer arranged on the inside of the casing (4) on an anticipated impact surface of one of the components of the latching mechanism (3) during the latching or unlatching movement (3).

Claims

1. A belt buckle for a safety belt system for locking a belt tongue comprising: a casing, a latching mechanism arranged in the casing, the latching mechanism including a frame forming an aperture, a spring element loading the latching mechanism in a locking direction of locking with the belt tongue, a damping element that contacts a bar component of the latching mechanism during a movement of the bar component in the locking direction of the latching mechanism, and the damping element is formed by a soft layer arranged on the inside of the casing extending through the aperture and positioned on an anticipated impact surface of the bar component of the latching mechanism during a locking movement in the direction of locking or an unlocking movement.

2. A belt buckle according to claim 1, further comprising: the soft layer is glued onto an inside surface of the casing.

3. A belt buckle according to claim 1, further comprising; the soft layer together with the casing are produced by a two shot injection molding process.

4. A belt buckle according to claim 1, further comprising; the soft layer is formed by an insert component that is inserted into a recess provided on an inside surface of the casing and which is secured against slipping out by the frame of the latching mechanism.

5. A belt buckle according to claim 1, wherein the soft layer is formed of a foam mass comprising an elastic polyurethane.

6. A belt buckle according to claim 1, further comprising; the thickness of the soft layer is such that the bar component of the latching mechanism moved during the locking movement of the latching mechanism in the direction of the soft layer submerges into the soft layer after the locking of the belt tongue.

7. A belt buckle according to claim 6, further comprising; the soft layer has a flat base section and a cushion-like damping section provided on the flat base section, wherein the soft layer is positioned on an inside surface of the casing so that the bar in an end phase of the locking movement submerges into the damping section.

8. A belt buckle according to claim 1, further comprising; the damping element forming a flat base section and a cushion like damping section forming the soft layer, the flat base section clamped between the casing and the frame with the damping section extending through the aperture.

9. A belt buckle according to claim 8, further comprising; a portion of the flat base section rests against an outside of the frame in a region surrounding the aperture such that the damping element cannot pass completely through the aperture.

10. A belt buckle according to claim 1, further comprising; the damping element affixed to the casing or formed integrally by the casing and extending through the aperture.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained below by means of a preferred realization example with reference to the annexed figures. Shown here are:

(2) FIGS. 1(a), 1(b), and 1(c) show a belt tongue with a latching mechanism and an insert component; with FIG. 1(a) showing the latching mechanism and belt tongue separated, FIG. 1(b) is similar to FIG. 1(a) but showing the insert component separated, and FIG. 1(c) showing the belt tongue fastened to the latching mechanism; and

(3) FIG. 2 shows a half casing of the belt buckle with the insert component arranged therein.

DETAILED DESCRIPTION

(4) Seen in FIGS. 1(a), 1(b), and 1(c) is a frame 2 with a latching mechanism 3 of a belt buckle arranged therein and a belt tongue 1 of a safety-belt device of a motor vehicle. As basic components, in addition to others that are important for the latching and unlatching mechanism of the belt tongue 1, the latching mechanism 3 includes a spring 13 and a bar 7. The belt tongue 1, in addition to a deflection section 15 with a through-opening 14 for the safety belt of the safety-belt device, includes an interlock plate 5 with a locking opening 6. When the belt tongue 1 with the interlock plate 5 is inserted into an insertion slot of the belt buckle, the bar 7, by means of a mechanism known to the state of the art and therefore not described in detail here, is swiveled due to the spring force exerted by the spring 13 and in this way engages the locking opening 6 of the interlock plate 5 so that the belt tongue 1 is then tightly held inside the belt buckle. This latching movement takes place after the previously described dead point has been overcome by a strong acceleration of the bar 7 and a sudden deceleration of the bar 7 in the locked position.

(5) Also provided is an insert component 8 that has a flat base section 11 and a cushion-like damping section 10 provided on the base section 11. The insert component 8 butts against the outside of the frame 2 and engages, by means of the cushion-like damping section 10, into an aperture 9 of the frame 2. The insert component 8 is positioned such in this position that the cushion-like damping section 10 comes to rest approximately opposite the front side of the bar 7 that has been swiveled into the unlocked position. In order to fix the insert part 8, it is inserted into a corresponding recess 12 of the half casing section of a casing 4 and, if required, glued in place there. The half casing has a structure including the casing edges and protruding ridges, which enables the insertion of the frame 2 with the latching mechanism 3 arranged inside it into only one position, in which the insert part 8 engages into the aperture 9 of the frame 2 with the damping section 10. In that way, the insert component 8 is fixed between the frame 2 and the half casing and, in addition, it cannot slip to the side due to the engagement into the recess 12.

(6) The damping section 10 has a cushion-like shape and extends from the surface of the base section 11 so that the insert component 8 has a considerably greater thickness in this section. The outside perimeter of aperture 9 is deliberately designed as smaller than the surface of the base section 11 so that the insert component 8 rests with the edge of the base section 11 against the outside of the frame 2 in the region of the edge surface of the aperture 9 and cannot pass completely through the aperture 9. The edge surface of the base section 11 thus forms a kind of abutment, by means of which the insert component 8 is wedged between the frame 2 and the half casing. The insert component 8 is made of a soft foam-like plastic, such as, for example, polyurethane. When the belt tongue 1 is inserted into the insertion slot of the belt buckle, the bar 7, supported by the spring force of the spring 13, is swiveled and engages the locking opening 6 of the interlock plate 5. The insert component 8 is arranged so that the damping section 10 covers an anticipated impact surface of the bar 7 on the inside of the half casing, so that the bar 7, in the final phase of the swivel movement, submerges with its front end section into the soft damping section 10. This results on the one hand in noise generation being reduced from the start, and on the other hand in the propagation of residual noise being additionally damped by the soft material of the insert component 8. Both effects contribute to a result where the belt tongue is locked into the belt buckle, noise emission outside is significantly reduced, and the locking procedure is quieter.

(7) The insert component 8 forms a soft layer on the half-casing of casing 4 which prevents a direct impact of the bar 7 on the surface of the harder casing 4. The insert component 8, or as the case may be the soft layer, is arranged on casing 4 so that it covers the section of casing 4 that is arranged opposite the front end of the tilted bar 7, the section of the casing being the section that the bar 7 would otherwise impact.

(8) Instead of the insert component 8, the soft layer can also be sprayed or molded directly onto the casing 4 in a two-stage injection molding process, in which case the assembly operation of inserting the insert part 8 can be omitted.

(9) It is particularly important for the noise reduction from the belt buckle that the soft layer, i.e. in this case the insert component 8, be arranged in casing 4 against the anticipated impact surface of the bar 7 in the locking direction of the latching mechanism 3. The locking direction is understood as the direction in which bar 7 of the latching mechanism moves to the side with its front end. The section of casing 4 on which the insert component 8 should be arranged is thus the section of casing 4 toward which bar 7 is swiveled with its free front end. If bar 7 is moved with another surface closer to casing 4 and can come to rest there, the insert part 8 or as the case may be the soft layer, could be assigned to this section of casing 4, or an additional soft layer could also be provided on another, second anticipated impact surface of casing 4. This, depending on the structure of the latching mechanism 3, can also be a surface of the casing 4 that is arranged laterally to the bar 7, as long as the rod, during the unlatching or latching movement, can come to rest against it.

(10) The thickness of the insert component 8 or, as the case may be, of the soft layer can be such that the bar 7 in each case comes to rest in a damping manner against the soft layer. Alternatively, the thickness of the soft layer can be such that the bar 7 or other parts of the latching mechanism 3 only come to rest against or submerge into the soft layer during extreme accelerations and extreme movements.

(11) Furthermore the frame 7 of the latching mechanism 3 can also be elastically supported against the casing 4 at least to a small degree by the insert component 8, by which means the structure-borne sound transmission from the frame 2 to casing 4 can be reduced.

(12) While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.