MXPA97005739A

MXPA97005739A - Integral module of steering wheel and bag

Info

Publication number: MXPA97005739A
Application number: MXPA/A/1997/005739A
Authority: MX
Inventors: Kay Ricks Merle; Vail Adams Gary; J Mannino Joseph; L Vigeant Peter
Original assignee: Morton International Inc; Tg North America Corporation
Priority date: 1996-08-12
Filing date: 1997-07-29
Publication date: 1998-02-01

Abstract

The wheel and spoke armatures of a car steering wheel are molded into a plastic body that presents the driver with a front surface that is not broken. The plastic body of the steering wheel includes a recess in its rear surface which is enclosed by a hub plate fixed to the steering column. The cavity and the hub plate serve as an air bag module and house the inflator and the air bag doubles therein. The front surface of the flywheel body can be marked, preferably on its hidden side, to form tear lines to release the expanding airbag.

Description

INTEGRAL FLYWHEEL AND AIR BAG MODULE TECHNICAL FIELD This invention relates to the field of vehicular air bags. More particularly, a single unit is associated with a steering wheel and air bag on the driver's side.

PREVIOUS TECHNIQUE The conventional driver's side air bag modules are separate units placed in a recess in the front of the steering wheel. This creates a crack that surrounds the air bag module where it meets the front surface of the steering wheel. This crack tends to pick up dust and is essentially undesirable. It would be preferable for the steering wheel to present the driver with a substantially unbroken surface. A means for overcoming this problem is described in European Patent Publication No. EP 0 648 661 A1, published April 19, 1995. This publication discloses a steering wheel having a seamless front surface in a body that is integral with the wheel of the steering wheel. The wheel portion is connected to elongated beams which connect the steering wheel mounting hub The air bag module is connected to the steering wheel central body and is also connected by screws to the elongated beams. Consequently, in order to service or replace the airbag module, it is necessary to remove the screws that interconnect the module with the spokes, then separate the screws that connect the wheel and the central body to the spokes. This allows the main body of the steering wheel and the connected airbag module to separate. Then it is necessary to remove the -module from the central body of the steering wheel. This results in an undesirable amount of work and it is expensive what would be desirable to imine. Accordingly, a main object of the present invention is to provide a flywheel in the form of a molded body having a non-rotatable front surface that can be separated in an operation to expose the airbag module. Other objects, features and advantages will become apparent from the following description and appended claims.

EXHIBITION OF THE INVENTION The invention comprises a steering wheel in the form of a molded body that spans the steering wheel and spokes. The molded body defines a cavity which is placed on a hub plate connected to the steering arrow. The cavity serves as the air bag module, housing both the double air bag and the inflator.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front view, or on the driver's side ', of a steering wheel and airbag module in accordance with the present invention; Figure 2 is a cross section taken substantially along the line 2-2 of Figure 1; Figure 3 is an enlarged partial cross-section, illustrating a way of retaining the airbag within the flywheel; Figure 4 is a plan view of an air bag retention ring usable in the present invention; and Figure 5 is a view similar to Figure 3, showing how to install the retainer ring of Figure 3.

BEST MODE FOR CARRYING OUT THE INVENTION In accordance with the present invention, a hub plate 10 having a recessed central region 12 is mounted in a hub 14 which is secured to the end of a steering column 16 by conventional means. A flywheel in the form of a mature wheel 18 mounted to one end of one or more beam reinforcement 2 integrally molded towards a plastic body 22 provides a non-broken surface 24 as shown in Figure 1. Body 22 it is formed with an internal cavity 26. The front surface of the body 22 overlapping the cavity 26 slides on the cavity side to form one or more tearing lines 28, 30 that are designed to open in a conventional manner to release the air pocket during activation.

The flywheel is mounted to the hub plate 10 by fastening elements such as screws extending through the hub plate 10 and into the beam reinforcements 20. When you moneta d this way, the beam armatures 20 extend radially outwardly from the hub plate and the wheel armature is co-located in a spaced plane of the hub plate 10 in a direction away from the steering column 16. Also secured detachably on the hub plate 10 by means of nuts and bolts 34 is a mounting flange 36 of a conventional inflator 38. The inflator 38 also extends downward towards the central region 12 recessed from the hub plate. The cavity 26 also encloses a bladder 40 of bent air. In this way it will be seen that the integral steering wheel described in its becomes the airbag module. ... When the airbag or its inflator is going to be replaced or is going to be replaced, it is only necessary to remove the screws 32, thus allowing the steering wheel to separate and completely reveal the airbag and the inflator. A race 42 that is frequently present on the back of the wheel can be removed or provided with access openings to reach the screws 32. Since the air bag module of this invention does not have a separate housing apart from the wheel itself , it is possible to achieve a simplified construction in the way of installing the airbag. The air bag 40 has a conventional round mouth 44 formed therein. The peripheral region surrounding this mouth may be formed between the mounting flange 36 of the inflator and the hub plate 10. This is illustrated in the amplified side view of Figure 3. As will be seen therein, the fabric of the air pocket 40 surrounding the mouth 44 is positioned between the flange 36 and the inflator and the hub plate 10. . In this position it is held and retained by means of the nuts and bolts 34 which serves to simultaneously mount the airbag and the inflator on the hub plate, thus achieving an economy of parts and installation work. If it is deemed necessary to increase the friction that has the mouth of the air bag 40, a retainer ring 46 of the type shown in Figure 4 and described and claimed in US Pat. No. 5,443,284 can be employed. The illustrated ring has four mounting holes 48 for receiving the bolts 34 that mount the inflator 38 to the hub plate 10. It is also perforated by eight U-shaped cuts around its periphery. The material within each cut is folded down to create eight tabs 50 which depend on the openings U-shaped 52. As illustrated in Fig. 5, the retainer ring is mounted on the fabric of the air bag 40 surrounding its mouth 44. Appropriate openings 54 are provided in the hub plate 10 to receive the tabs after they have perforated the fabric. If desired, the tabs can be longer and stamped below the cube plate for even more security. In addition to increasing the retention force on the air bag, the retainer ring can be made of a thermally insulating material to help protect the airbag fabric from the intense heat generated by some inflator gas generators. It is believed that the many advantages of this invention will now be apparent to those skilled in the art. It will also be evident that a number of variations and modifications can be made to it without abandoning its spirit and scope. Consequently, the foregoing description should be considered as illustrative only, rather than limiting. This invention is limited only by the scope of the following clauses.

Claims

CLAIMS:

1. - A self-propelled steering wheel comprising: a hub plate connectable directly to a steering column and extending substantially radially outwardly therefrom; the cube plate having a lowered central region; a beam armature having a first end directly connectable to the hub plate and a second end, when connected in this manner, positioned radially outwardly-of the hub plate in a spaced plane of the hub plate in an address away from the address column; a wheel armature in the spaced plane secured to the second end of the beam armor; a one-piece molded plastic body - with and encompassing the beam and wheel armatures and defining an internal cavity placed on the hub plate when the beam armature is directly connected to the hub plate; an air bag inflator mounted on the CJJ plate bo in the central mid-range region and inside the molded plastic body cavity; a bent air pocket within the cavity, the air bag having the mouth positioned to receive inflating gas from the inflator; the inflator and air bag being fully exposed when the beam armature is separated from the bucket plate and the molded body removed; and elements for releasably securing the first end of the beam armor to the hub plate.

2. The steering wheel of claim 1, comprising: a plurality of beam armatures, each having a first end directly connectable to the hub plate and a second end positioned radially outwardly from the hub plate; and wherein the wheel armature is secured to the second end of each of the spoke armatures.

3. The steering wheel of claim 1, comprising: a mounting flange surrounding the inflator; the mouth of the air bag being placed between the mounting plate and the hub plate; and elements for releasably securing the mounting flange on the hub plate and simultaneously securing the mouth of the air bag between the flange and the hub plate.

4. The steering wheel of claim 3, wherein the element for releasably securing further comprises: a retainer ring surrounding the mouth of the intermediate air bag to the hub plate and the inflator flange; and an element extending from the retainer ring to perforate the air bag in spaced positions around the mouth.

5. The steering wheel of claim 4, wherein the piercing elements are received in aligned openings in the hub plate.

6. The steering wheel of claim 3, comprising: a plurality of beam armatures, each having a first end connectable to the hub plate and a second end positioned radially outwardly of the hub plate; and wherein the wheel armature is secured at the second end of each of the beam armatures. 1 . - The steering wheel of claim 4, comprising: a plurality of beam armatures, each having a first end connectable to the hub plate and a second end positioned radially outwardly from the hub plate; wherein the wheel armature is secured at the second end of each of the beam armatures. 8. The steering wheel of claim 5, comprising: a plurality of beam armatures, each having a first end connectable to the hub plate and a second end positioned radially outwardly from the hub plate; and wherein the wheel armature is secured at the second end of each of the beam armatures.