SEAT BELT RETRACTOR

Abstract

A seat belt retractor (40) having a belt spool (14), a seat belt (12) that can be wound thereon to a belt spool, and at least a first and a second assembly (1, 2), wherein the first and the second assembly (1, 2) are arranged coaxially to each other and at a first angle (A) to the rotational axis (B) of the belt spool (14) and are connected together by a flex coupling or an angular gear.

Claims

1. A seat belt retractor comprising; a belt spool, a seat belt that can be wound thereon to a belt spool, at least a first and a second assembly each for controlling or influencing the winding or extraction of the seat belt on the belt spool, and the first and the second assembly are arranged coaxially to each other and at a first angle to the rotational axis of the belt spool.

2. The seat belt retractor according to claim 1 further comprising, the first assembly is an electric motor and the second assembly is a gear that transmits a rotary driving movement of the electric motor to the belt spool.

3. The seat belt retractor according to claim 1 further comprising, a third assembly is provided for controlling or influencing the winding or extraction of the seat belt on the belt spool, which is arranged coaxially and in series to the belt spool or the first or the second assembly.

4. The seat belt retractor according to claim 3 further comprising, the third assembly is a force limiting device.

5. The seat belt retractor according to claim 3 further comprising, a fourth assembly is provided for controlling or influencing the winding or extraction of the seat belt on the belt spool, which is arranged coaxially and in series to the belt spool or the first or the second assembly.

6. The seat belt retractor according to claim 5 further comprising, the fourth assembly is an irreversible belt tightening mechanism.

7. The seat belt retractor according to claim 5 further comprising, the third and fourth assembly are arranged coaxially and in series to each other.

8. The seat belt retractor according to claim 1 further comprising, the belt spool is indirectly or directly connected to the first or the second assembly via an angular gear or a flex shaft.

9. The seat belt retractor according to claim 1 further comprising, a housing is provided with at least first and second housing parts, and the belt spool and at least one of the first or second assemblies are arranged in different ones of the first and second housing parts.

10. The seat belt retractor according to claim 9 further comprising, the first and second housing parts, in which the belt spool and the assemblies are arranged, are arranged to each other at an angle of their longitudinal axes, which corresponds to the first angle of the arrangement of the first and second assembly to the rotational axis of the belt spool.

11. The seat belt retractor according to claim 9 further comprising, the belt spool and the first and second assemblies are arranged at a distance from each other and are mutually connected via a flex shaft, and at least one housing center part is provided between the first and second housing parts, which mutually connects the first and second housing parts which are positioned at an angle with respect to each other.

12. The seat belt retractor according to claim 11 further comprising, other functional components allocated to the first or the second assemblies or the belt spool are arranged in the housing center part.

13. The seat belt retractor according to claim 9 further comprising, the first and second housing parts are formed by respective elongated U-profiles.

14. The seat belt retractor according to claim 13 further comprising, webs oriented vertically to the longitudinal axes of the U-profiles, which are rotationally connected to the U-profiles with reference to the longitudinal axes of the U-profiles, are provided in the U-profiles.

15. The seat belt retractor according to claim 14, further comprising, at least one of the first or second assemblies or the belt spool are supported in at least one of the webs.

16. The seat belt retractor according to claim 14 further comprising, further functional components of the assemblies or the belt spool are arranged in at least one of the webs.

17. The seatbelt retractor according to claim at 1 further comprising, the first assembly is an electric motor and the second assembly is one of an irreversible belt-tightening mechanism or a force limiting device, and the first and the second assemblies are connected via a flexible shaft.

18. The seatbelt retractor according to claim at 1 further comprising, the first assembly is an electric motor and the second assembly is an irreversible belt-tightening mechanism and a third assembly in the form of a force limiting device, a flexible shaft is positioned between the first and the second assemblies with the force limiting device coupled to the irreversible belt-tightening mechanism.

19. The seatbelt retractor according to claim at 1 further comprising, the first assembly is an electric motor and the second assembly is a gear reduction unit, the first and the second assemblies connected with a third and a fourth assembly by a flexible shaft position between the second and third assemblies.

20. The seatbelt retractor according to claim at 19 further comprising, the third assembly is an irreversible belt-tightening mechanism and the fourth assembly is a force limiting device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention will be described below with reference to the included figures with the aid of preferred embodiments, wherein:

[0026] FIG. 1 shows a seat belt retractor according to the invention having a flex shaft and an open and closed housing; and

[0027] FIGS. 2 to 5 show different views of a seat belt retractor according to the invention having an angular gear; and

[0028] FIG. 6 shows the seat belt retractor according to the invention having the flex shaft without housing.

DETAILED DESCRIPTION

[0029] FIGS. 1 and 6 depict a seat belt retractor 40 according to the invention with a safety belt 12 that can be wound on the belt spool 14. The seat belt retractor 40 has a housing 7 consisting of two spaced housing parts 8 and 9 and a housing center part 10 arranged between the housing parts 8 and 9, which is omitted for better viewing in the representation of FIG. 6. The housing parts 8 and 9 as well as the housing center part 10 are configured as elongated U-profiles and are arranged in such a way that the two spaced housing parts 8 and 9 mutually enclose an angle E that is smaller than 180 degrees but greater than 90 degrees with their longitudinal axes D and are connected to each other via the housing center part 10. The open sides of the housing parts 8 and 9 as well as the housing center part 10 are respectively covered via covering parts 13 to form a closed profile, wherein the covering parts 13 were omitted for better visibility in the lower depiction.

[0030] Beside the belt spool 14, the seat belt retractor has a first and second assembly 1 and 2 in the form of an electric motor and a gear unit and a third and fourth assembly 3 and 4 in the form of a force limiting device and a pyrotechnic irreversible tightening device, respectively. In the housing parts 8 and 9 are furthermore provided several webs 11 which divide the hollow space in the U-profiles into segments and which are arranged vertically to the longitudinal axes D of the housing parts 8 and 9 and are supported in a form-fitting and rotationally connected manner with reference to the longitudinal axes D on the inner walls of the housing parts 8 and 9. The webs 11 serve to bear the assemblies 1, 2, 3 and 4 and the belt spool 14, as well as to accommodate further functional components of the assemblies 1, 2, 3, 4 and the belt spool, such as, for example, switching mechanisms, sensing devices, electronic components and lines, et cetera.

[0031] The first and second assembly 1 and 2 are respectively, an electric motor and a gear unit arranged coaxially and in series to the electric motor, and are aligned with their rotational axes or longitudinal axes at a first angle A to the rotational axis of the belt spool 14. The gear unit is connected or can be connected to the belt spool 14 via an intermediately connected coupling via a flex shaft 6 by the housing center part 10 via the third and fourth assembly 3 and 4. The first and second assembly 1 and 2 are arranged coaxially and in series to each other, so that the seat belt retractor 40 has a slender elongated shape in this region. The belt spool 14 is likewise aligned coaxially and in series to the third and fourth assembly 3 and 4, so that the seat belt retractor 40 also has an elongated slender shape in this section. The housing center part 10 serves for bridging the distance between the housing parts 8 and 9 and connects the housing parts 8 and 9 to the uninterrupted housing 7. The free space in the housing center part 10 is used here again to accommodate a tightening drive tube 15 of the pyrotechnic tightening device. The free space in the housing center part 10 can of course be used beside the tightening drive tube to accommodate further functional components of the different assemblies 1, 2, 3 or 4. The housing center part 10 can be preferably configured more narrow and smaller in its cross sectional surface vertically to the flex shaft 6 than the dimensions of the housing parts 8 and 9 vertically to their longitudinal axes D. The flex shaft 6 is furthermore encased and/or guided by means of a dimensionally stable guiding part. As an alternative or in addition, the flex shaft is also supported at an additional bearing point, which can be realized, for example, by an additional web 11 in the housing center part 10 or in the edge section of the housing parts 8 and 9.

[0032] Due to the proposed arrangement of the two assemblies 1 and 2 at the first angle A to the belt spool 14, the seat belt retractor 40 itself is adapted by a corresponding design of the first angle A to an existing free space in a vehicle seat. The use of the flex shaft 6 thereby additionally provides the advantage that the assemblies 1 and 2 can also be arranged at a distance to the belt spool 14, as long as the free spaces available in the vehicle seat are also arranged at a distance with respect to each other. The flex shaft 6 makes possible particularly the arrangement of the assemblies 1 and 2 at different angles A and distances to the belt spool 14 without having to change the design, aside from the housing 7, for this purpose. The seat belt retractor 40 can thereby be better adapted to the geometry of the free space available in the vehicle seat. The housing parts 8 and 9 and the housing center part 10 thus form a slender elongated housing 7 together with the covering parts 13 which cover the assemblies 1, 2, 3 and 4 as well as the belt spool 14 to the outside and protect them from mechanical influences. The housing 7 can however additionally also be used for stiffening the seat structure or other structures of the vehicle and can be correspondingly shaped and designed for this purpose. In the proposed configuration, the seat belt retractor 40 can be arranged, for example, in an upper edge of the seat structure of a backrest, wherein the belt spool 14 is arranged at one end of the seat belt retractor 40, so that the safety belt 12 is guided from a lateral section of the upper edge of the backrest over the shoulder on the upper body of a passenger seated in the vehicle seat in the assembled position of the seat belt retractor 40.

[0033] The angle E between the longitudinal axes D of the housing parts 8 and 9 corresponds to the first angle A between the longitudinal or rotational axes of the belt spool 14 and the first and second assembly 1 and 2. The first angle A between the assembly groups 1 and 2 and the belt spool 14 is practically repeated between the housing parts 8 and 9.

[0034] An alternative embodiment of the invention can be seen in FIGS. 2 to 5, in which the assemblies 1, 2, 3 and 4 are arranged coaxially and in series to each other. An angular gear 5 is provided between the third assembly 3, that is, the force limiting device, and the belt spool 14, so that the belt spool 14 can be arranged at a first angle A, for example, greater than 90 degrees, equal to 90 degrees, or less than 90 degrees to the longitudinal axes or rotational axes of the assemblies 1, 2, 3 and 4. The assemblies 1, 2, 3 and 4 thus form a slender, elongated subunit of the seat belt retractor 40, on which the belt spool 14 is arranged laterally at the first angle A. The seat belt retractor 40 can thus preferably be arranged in such a way in the vehicle seat that the assemblies 1, 2, 3 and 4 are arranged in a lateral section in an approximately vertical alignment within the structure of the backrest, and the belt spool 14 is arranged in a lateral section of the upper edge of the backrest. As angular gear 5, for example, one can use a pair of bevel gears, worm gears, crank drive mechanisms, helical gears, et cetera, which are represented herein.

[0035] In the exemplary embodiment of FIG. 1, the first and second assemblies, that is, the electric motor with the corresponding gear unit, are oriented at an angle to the belt spool 14 and the third and fourth assembly 3 and 4, so that the rotary movement of the gear unit must be deflected at an angle, which has the advantage that the torque to be deflected at this point is very small, so that the flex shaft 6 is sufficient here.

[0036] In the exemplary embodiment of FIGS. 2 to 5, only the belt spool 14 is oriented at an angle to the assemblies 1, 2, 3 and 4 or, otherwise expressed, the assemblies 1, 2, 3 and 4 arranged coaxially and in series to each other are oriented at an angle to the belt spool 14. The torque acting between the belt spool 14 and the force limiting device, which is clearly greater in the retention case, must thus be deflected. The more highly reliable and accurate angular gear 5, in which the rotary movement is transmitted by mutually meshing gearings or other form-fitting connections in a fixed special allocation to each other, is advantageously provided for this purpose.

[0037] Since the angular gear for a functionally secure operation presupposes a functionally secure engagement of the gears over a long service life, the angular gear 5 is additionally encapsulated by a separate housing, so that the deflection point is additionally shielded with respect to the interior of the housing 7.

[0038] Throughout this description assemblies are described, including the assemblies 1, 2, 3 and 4. These assemblies are provided to influence or control the retraction and extraction of webbing from the belt spool 14. For example, assembly 1 in the form of an electric motor provides rotary motion to rotate spool 14 which can be in the extraction and/or retraction directions. Assembly 2 in the form of a gear unit provides a gear reduction between the output of electric motor 1 and the drive through a flex shaft or other coupling to other assemblies coupled with the belt spool 14. Assembly 3 in the form of a force limiting device is provided to limit tension on belt webbing during a restraint event which is provided for controlling the restraining effect and forces acting on an occupant during an impact. Assembly 4 the form of a pre-tensioner is designed to minimize slack of the belt webbing by forcibly retracting webbing onto belt spool number 14 upon the detection of an impact condition. These assemblies 1, 2, 3 and 4 are connected with one another in a series manner and combine to provide desired control of belt webbing movement through the belt spool 14.

[0039] 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.