Belt-retractor housing shell

Abstract

A belt retractor casing shell having a cup-shaped configuration comprises a front wall (14) as well as a circumferential wall (16) extending from the front wall (14), the front wall (14) including an annular zone (44) weakened vis--vis the radially inside and/or outside adjacent portion around a center (42).

Claims

1. A belt retractor casing shell which has a cup-shaped configuration and includes a front wall (14) as well as a circumferential wall (16) extending from the front wall (14), the front wall (14) including an annular zone (44) around a center (42), the annular zone (44) being weaker than an adjacent portion of the front wall (14) that is at least one of radially inside and radially outside the annular zone (44), wherein a reinforcing structure including ribs (36, 38) is provided at an inside (18) of the front wall.

2. The belt retractor casing shell according to claim 1, wherein the reinforcing structure includes cobweb-like arranged ribs (36, 38).

3. The belt retractor casing shell according to claim 1, wherein in the weakened annular zone (44) the ribs (36, 38) of the reinforcing structure are configured to have a reduced cross-section, at least in portions.

4. The belt retractor casing shell according to claim 1, wherein the center (42) is formed to be free of ribs.

5. The belt retractor casing shell according to claim 1, wherein the weakened annular zone (44) starts directly radially outside a second circular rib (38) peripheral around the center (42).

6. The belt retractor casing shell according to claim 1, wherein on the outer periphery of the front wall (14) radially inwardly extending positioning ribs (46) ending ahead of the weakened annular zone (44) are provided the cross-section of which is larger than the cross-section of the ribs (36, 38) of the reinforcing structure outside the weakened annular zone (44).

7. The belt retractor casing shell according to claim 1, wherein the casing shell (12) is made of plastic material.

8. A belt retractor comprising a belt retractor casing shell according to claim 1, wherein a gap is provided between the inside (18) of the front wall and other components of the belt retractor (10) in the state mounted on the belt retractor (10).

9. The belt retractor according to claim 8, wherein the weakened annular zone (44) is spaced further from an outside of a functional component cover (24) than the adjacent portion of the front wall that is at least one of radially inside and radially outside of the weakened annular zone (44).

10. The belt retractor casing shell according to claim 1, wherein in the weakened annular zone (44) the ribs (36, 38) of the reinforcing structure are configured to have a reduced height, at least in portions.

11. The belt retractor casing shell according to claim 1, wherein at least part of the ribs are concentric about the center.

12. The belt retractor casing shell according to claim 1, wherein at least part of the ribs extend radially outward from the center.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Hereinafter the invention will be described in detail by way of an embodiment with reference to the enclosed drawings, in which:

(2) FIG. 1 shows a schematic sectional view across a belt retractor casing shelf according to the invention mounted to a belt retractor according to the invention;

(3) FIG. 2 shows a belt retractor casing shell according to the invention in a schematic perspective view;

(4) FIG. 3 is a top view on the belt retractor casing shell from FIG. 2;

(5) FIG. 4 is a further top view on the belt retractor casing shell from FIG. 2; and

(6) FIG. 5 shows a schematic sectional view of a snap lock of a fastening pin of the belt retractor casing she from FIG. 1 and a locking portion of the belt retractor.

DESCRIPTION

(7) FIG. 1 illustrates a belt retractor 10 which is closed off laterally outwardly by a belt retractor casing shell 12.

(8) The casing shell 12 includes a front wall 14 substantially even from outside as well as a circumferential wall 16 which is circumferential around the front wall 14 and protrudes perpendicularly therefrom. The inside 15 of the front wall 14 faces the functional components of the belt retractor 10 in the illustrated state mounted on the belt retractor 10, while the outside 20 of the front wall 14 faces away from the belt retractor 10.

(9) Typically two casing shells 12 are provided which are fastened on both sides of a belt reel (not shown) to a frame 22 of the belt retractor 10.

(10) The casing shells 12 close off the belt retractor 10 laterally outwardly and in the shown example cover all functional components such as the belt reel, an inertia sensor as well as a functional component cover 24 which e.g. covers the inertia sensor and in which a bearing 26 for the belt reel is formed in this case.

(11) The casing shell 12 is connected, via plural fastening pins 28, to appropriate locking members 30 provided e.g. on the functional component cover 24. The fastening pins 28 are designed so that they are engaged in the locking elements 30 via an axial portion extending over several millimeters and in this manner the casing shell 12 is tightly connected to the belt retractor 10. This is illustrated in detail in FIG. 5.

(12) The free edge 32 of the circumferential wall 16 in this example rests peripherally on an outer surface 34 of the frame 22 of the belt retractor 10.

(13) On the inside 18 of the front wall 14 a reinforcing structure is formed which in this example consists of cobweb-like arranged ribs, wherein radially extending ribs 36 and concentrically circularly extending ribs 38 are provided. All circular ribs 38 are equally spaced here, e.g. at approximately 0.5 to 2 cm.

(14) For reasons of clarity only one rib of the respective type of ribs is provided with a reference numeral in the Figures.

(15) In the shown example all radial ribs 36 end at the innermost circular rib 36 which encloses a center 42 of the casing shell 12. The center 42 is located above the bearing 26 of the belt reel in the mounted state (cf. FIG. 1). The distance of the innermost circular rib 38 from the center 42 in this case is about 0.5 cm. Insides the rib 38 the inside 18 of the front wall is formed to be flat.

(16) In the shown embodiment, between the center 42 and the circumferential wall 16 an annular weakened zone 44 is formed between a radius r.sub.1 and a radius r.sub.2 (shown in hatched lines in FIG. 3). In this example the weakened zone 44 extends directly radially outside of the second circular rib 38 peripheral around the center 42 and reaches over the major part of the surface of the front wall 14 up to and including the fourth circular rib 38 peripheral around the center 42 which forms the last completely circularly closed rib 38 ahead of the circumferential wall 16.

(17) In the lower corner on the left in the Figures the weakened zone 44 extends over a segment-shaped area of about 60 C. beyond the radius r.sub.2 over two further circular ribs 38.

(18) Within the weakened zone 44 in this example both the radial ribs 36 and the circular ribs 38 are reduced as to their height, in this case by half vis--vis the residual radial and circular ribs 36, 38 having the same height outside the weakened zone 44.

(19) The weakened zone 44 could also be weakened in a different manner, for example by reducing the thickness of the front wall 14 or by reducing the width of the ribs 36 and/or the ribs 38, or in that only the cross-section (height and/or width) of one of the two types of ribs 36, 38 or particular ribs 36, 38 would be reduced in cross-section only in portions. The ribs 36, 38 could as well be completely missing at least in portions.

(20) The height of the ribs 36, 38 is defined by the distance from the surface of the inside 18 of the front wall 14 to the free end of the respective rib 36, 38. The width of the ribs 36, 38 is defined in parallel to the course of the inside 18 of the front wall 14 in the radial direction (circular ribs 38) or circumferential direction (radial ribs 36).

(21) The weakened zone exhibits lower rigidity and higher flexibility than the surrounding portions of the front wall 14, thus influencing the vibration behavior of the casing shell 12 so that interfering frequency bands, especially within the range of 1.6 kHz, 2.0 kHz, 2.5 kHz and 4.0 kHz may be reduced by up to 5 dB when white noise is applied vis--vis a casing shell 12 in which all ribs 36, 38 have the same cross-section over the entire inside 18 of the front wall 14.

(22) Moreover, plural positioning ribs 46 are provided which are formed integrally with the circumferential wall 16 and the front wall 14 on the inside 18 of the casing shell 12 and which extend radially inwardly but end ahead of the weakened zone 44. Only in FIG. 4 all positioning ribs 46 are marked by reference numerals. The positioning ribs 46 in this case serve for improving the clamping effect between the circumferential wall 16 of the casing shell 12 and the functional component cover 24 and, resp., the frame 22 of the belt retractor 10 and to fix the circumferential wall 16 as tightly as possible to these components.

(23) The cross-section of the positioning ribs 46, especially their width but also their height, is selected to be larger than that of the radial ribs 38 outside the weakened zone 44. The width can be selected to be 1.2 to 2.5 times as large, whereas the height is considerably higher and reaches up to nearly below the free edge 32 of the circumferential wall 16.

(24) The height of the circumferential wall 16 as well as the height of the ribs 36, 38 at the inside 18 of the front wall 14 is selected so that in the mounted state the inside 18 of the front wall 14 contacts no other component of the belt retractor 10. In this case, a continuous gap exists between the inside 18 of the front wall 14 and the outside of the functional component cover 24.

(25) In the area of the weakened zone 44 the distance above the ribs 36, 38 is fairly larger, for example twice to four times as large as in the residual area of the front wall 14 above the ribs 36, 38. This permits higher vibration amplitude for the front wall 14 in the weakened zone 44 without contacting the functional component cover 24.

(26) The casing she 12 in this example is made of plastic material and is fabricated together with the positioning ribs 46, the ribs 36, 38 and the fastening pins 28 as a one-piece injection molded part.

(27) Apart from the ribs 36, 38 the positioning ribs 48 and the fastening pins 28, the inside 18 of the front wall 14 forms a substantially planar surface. In this case also the outside 20 of the front wall 14 is a substantially planar surface.