Claims:We claim:

1. A multifunctional seat-belt anchorage system for seat-belt mounting in an automobile underbody structure, wherein the system comprises:

- a rear floor for supporting the passenger and/or luggage load;
- a central floor for supporting the passenger load;
- a cross-member for rear floor for increasing the torsional stiffness of the body-in-white (BIW) of the automobile;
- a long-member for increasing the bending stiffness of BIW and to support in rear crash;
- a reinforcement plate fixed on the long-member for further increasing the bending stiffness of BIW and to support in rear crash; and
- a seat-belt anchorage bracket spot-welded reinforcement plate fixed on the long-member for supporting the seat-belt anchorage loads.

2. Multifunctional seat-belt anchorage system as claimed in claim 1, wherein seat-belt anchorage system comprises a seat-belt anchorage bracket having a closed cross-section including an inner panel and an outer panel and the inner and outer panel are spot-welded to the vehicle underbody structure.

3. Multifunctional seat-belt anchorage system as claimed in claim 1, wherein the long-member comprises a straight narrow end and a wider profiled end for housing the seat-belt anchorage bracket.

4. Multifunctional seat-belt anchorage system as claimed in claim 1, wherein the reinforcement plate is fixed on the long-member by means of welding.

5. Multifunctional seat-belt anchorage system as claimed in claim 4, wherein the seat-belt anchorage bracket is spot-welded on the reinforcement plate by placing the bracket in an oblique direction with the cross-section thereof disposed parallel to the axial loading direction for facilitating shear loading the spot-welds.

6. Multifunctional seat-belt anchorage system as claimed in anyone of the claims 1 to 5, wherein an embossed portion is configured on the top face of the seat-belt anchorage bracket.

7. Multifunctional seat-belt anchorage system as claimed in anyone of the claims 1 to 6, wherein a weld-nut is welded on the embossed portion of the seat-belt anchorage bracket for providing a predetermined bearing area to distribute the tension loads on the vertical walls thereof, so as to reduce the local strain on the bracket.

8. Multifunctional seat-belt anchorage system as claimed in anyone of the claims 1 to 7, wherein a plurality of side flanges are configured on the seat-belt anchorage bracket for preventing any buckling of the seat-belt anchorage bracket in the transverse direction during loading thereof.

9. Multifunctional seat-belt anchorage system as claimed in anyone of the claims 1 to 8, wherein the seat-belt anchorage bracket is configured of a single metallic plate, preferably a steel plate.

10. Multifunctional seat-belt anchorage system as claimed in anyone of the claims 1 to 9, wherein the seat-belt anchorage bracket is placed in an oblique direction on the reinforcement plate of the long-member for fixing, the cross-section thereof, preferably by welding, parallel to the axial loading direction of the seat-belt anchorage and for facilitating the shear loading of the spot welds welded thereon.

Dated this day of 29th December, 2015. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention generally relates to safety restraints for motor vehicles. In particular, the invention relates to seat belt anchorages for an automobile seat mounting. More particularly, the invention relates to multi-functional automotive seat-belt anchorage system, e.g. seat-belt anchoring bracket placed in the vehicle underbody structure.

BACKGROUND OF THE INVENTION

It is well-known that seat-belt anchorages play an important role in vehicle occupants’ safety. Sled testing as well as computational simulation has established that seat-belt anchorages have a strong effect on the automobile occupant kinematics.

The concept of designing the structure for vehicular seat belt anchorages placed in body structure can eliminate the undesired twisting loads acting on the bracket structure and thereby reduce the time and cost involved with design Iteration and validation. The concept can also increase the reliability of design to meet regulatory requirements. The zones and the strength under proof loads is defined for the Seat-belt anchorages the Indian Standard AIS 16, which is equivalent to ECE Regulation No. 14 concerning the Uniform provisions concerning the approval of vehicles with regard to safety-belt anchorages, ISOFIX anchorages systems and ISOFIX top tether anchorages. These Standards specify the safety restraints for motor vehicles, whereby the seat belt anchorage should be able to sustain a load of 22.5 kN (for a 2 point belt) and 13.5 kN (for a 3 point belt).

PRIOR ART

US4470619 discloses an automobile seat belt anchor attachment structure for attaching a seat belt anchor to a pillar structure, the attachment structure including inner and outer pillar panels which are welded together to form a closed cross-section. The attachment structure further including a stiffening panel secured to the pillar structure and a nut carrying plate secured to the stiffening panel with an anchor attaching nut provided thereon. The nut plate has high strength against forces both perpendicular and parallel to the base of the nut plate. An impact load applied to the anchor attachment, is prevented from deforming the nut plate.

DISADVANTAGES WITH THE PRIOR ART

However, the benchmark (conventional) seat-belt anchorage designs tend to have two directional angular load acting on the bracket leading to undesired turning and twisting the bracket during loading of the bracket.

IMPORTANT DEFINITIONS

Seat means a structure which may or may not be integral with the vehicle structure complete with trim, intended to seat one adult person. The term covers either an individual seat or part of a bench seat intended to seat one person.

Belt anchorages mean the parts of the vehicle structure or the seat structure or any other part of the vehicle to which the safety-belt assemblies are to be secured.

Effective belt anchorage means the point used to conventionally determine the angle of each part of the safety-belt in relation to the wearer, i.e. the point to which a strap would need to be attached to provide the same lie as the intended lie of the belt when worn, and which may or may not be the actual belt anchorage depending on the configuration of the safety-belt hardware at its attachment to the belt anchorage.

For example, in case where a strap guide is used on the vehicle structure or on the seat structure, the middle point of the guide at the place where the strap leaves the guide on the belt wearer's side, shall be considered as the effective belt anchorage; and where the belt runs directly from the wearer to a retractor attached to the vehicle structure or the seat structure without an intervening strap guide, the effective belt anchorage shall be considered as being the intersection of the axis of the reel for storing the strap with the plane passing through the centre line of the strap on the reel.

Seat type means a category of seats which do not differ in such essential respects as: the shape, dimensions and materials of the seat structure, the types and dimensions of the adjustment systems and all locking systems, and the type and dimensions of the belt anchorages on the seat, of the seat anchorage and of the affected parts of the vehicle structure.

Safety Belt (Seat-belt, Belt) means an arrangement of straps with a securing buckle, adjusting devices and attachments which are capable of being anchored to the interior of a motor vehicle and designed to diminish the risk of injury to the wearer in the event of collision or of abrupt deceleration of the vehicle, by limiting the mobility of the wearer’s body. Such an assembly is generally referred as a “belt-assembly”, a term also embracing any device for energy absorption or belt-retraction: These may be of the following types:

Two-Point (lap) Belt means a belt which passes across the front of the wearer’s pelvic lap region and constructed so as to extend over the lap area from both extremities of the lap and fixed at 2 points (see Figure ). These are generally non-retracting (static) type.

Three-Point Belt means a belt which passes diagonally across the front of the chest from the hip to the opposite shoulder and intended to constrain the wearer’s lap and upper body and constructed so that a continuous belt is fixed to a fitting at its one end and its other end, after passing over the passenger’s shoulder and then across the lap area after passing through slip guide and finally terminated at the fitting and supported at three points (see Figure ). These belts could be retracting type or non-retracting (static) type.

Seat anchorage means the system by which the seat assembly is secured to the vehicle structure, including the affected parts of the vehicle structure.
Thorax load limiter function means any part of the safety-belt and/or the seat and/or the vehicle intended to limit the level of the restraint forces applying to the occupant thorax in case of a collision.

ISOFIX is a system for the connection of child restraint systems to vehicles which has two vehicle rigid anchorages, two corresponding rigid attachments on the child restraint system and a mean to limit the pitch rotation of the child restraint system.

ISOFIX anchorages system means a system made up of two ISOFIX low anchorages which is designed for attaching an ISOFIX child restraint system in conjunction with an anti-rotation device.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a vehicular seat-belt anchorage system, which eliminates the undesired twisting loads acting on the bracket structure.

Another object of the present invention is to provide a vehicular seat-belt anchorage system, which reduces the time and costs involved with design iteration and validation.

Still another object of the present invention is to provide a vehicular seat-belt anchorage system, which satisfies all the mandatory requirements concerning the positioning thereof with the nearby structure.

Yet another object of the present invention is to provide a vehicular seat-belt anchorage system, which satisfies all the mandatory requirements concerning the orientation thereof with the nearby structure.

A further object of the present invention is to provide a vehicular seat-belt anchorage system, which satisfies all the mandatory requirements concerning the joinery thereof with the nearby structure.

A still further object of the present invention is to provide a vehicular seat-belt anchoring bracket placed in the vehicle underbody structure, which meets the international regulations for safety of vehicle occupants.

A yet further object of the present invention is to provide a vehicular seat-belt anchorage system which offers a simple orientation of the bracket.

One more object of the present invention is to provide a vehicular seat-belt anchorage system, which provides improved seat-belt anchorage bracket joinery in terms of behaviour of the seat anchorage structure.

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a multifunctional seat-belt anchorage system for seat-belt mounting in an automobile underbody structure, wherein the system comprises:

- a rear floor for supporting the passenger and/or luggage load;

- a central floor for supporting the passenger load;

- a cross-member for rear floor for increasing the torsional stiffness of the body-in-white (BIW) of the automobile;

- a long-member for increasing the bending stiffness of BIW and to support in rear crash;

- a reinforcement plate fixed on the long-member for further increasing the bending stiffness of BIW and to support in rear crash; and

- a seat-belt anchorage bracket spot-welded reinforcement plate fixed on the long-member for supporting the seat-belt anchorage loads.

Typically, the seat-belt anchorage system comprises a seat-belt anchorage bracket having a closed cross-section including an inner panel and an outer panel and the inner and outer panel are spot-welded to the vehicle underbody structure.

Typically, the long-member comprises a straight narrow end and a wider profiled end for housing the seat-belt anchorage bracket.

Typically, the reinforcement plate is fixed on the long-member by means of welding.

Typically, the seat-belt anchorage bracket is spot-welded on the reinforcement plate by placing the bracket in an oblique direction with the cross-section thereof disposed parallel to the axial loading direction for facilitating shear loading the spot-welds.

Typically, an embossed portion is configured on the top face of the seat-belt anchorage bracket.

Typically, a weld-nut is welded on the embossed portion of the seat-belt anchorage bracket for providing a predetermined bearing area to distribute the tension loads on the vertical walls thereof, so as to reduce the local strain on the bracket.

Typically, a plurality of side flanges are configured on the seat-belt anchorage bracket for preventing any buckling of the seat-belt anchorage bracket in the transverse direction during loading thereof.

Typically, the seat-belt anchorage bracket is configured of a single metallic plate, preferably a steel plate.

Typically, the seat-belt anchorage bracket is placed in an oblique direction on the reinforcement plate of the long-member for fixing, the cross-section thereof, preferably by welding, parallel to the axial loading direction of the seat-belt anchorage and for facilitating the shear loading of the spot welds welded thereon.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1a shows the long-member configured with seat-belt anchorage bracket in accordance with the present invention showing the important directions therein.

Figure 1b shows a bracket placed in an oblique direction (figure 2) for making the cross-section parallel to the axial loading direction and the spots loaded in shear in accordance with the present invention.

Figure 2 shows a closed cross-section structure comprising of inner and outer panels which are spot welded to the vehicle under body.

Figure 3 shows the vehicular seat schematically depicting the sear-belt anchorage assembly.

Figure 4 shows an enlarged view of the bracket in accordance with the present invention having side flanges.

Figure 5a to 5c show the load distribution in the bracket in the initial state thereof without any loading.

Figure 6a to 6c show the load distribution in the bracket at half-load.

Figure 7a to 7c show the load distribution in the bracket at full-load.

Figure 8a and 8b show an enlarged side view and top view respectively of the seat-belt anchorage assembly in accordance with the present invention.

Figure 9a to 9f show the various structural components of the seat-belt anchorage system configured in accordance with the present invention.

Figure 10a shows the long-member configured with the seat-belt anchorage bracket in accordance with the present invention in a perspective view from one end thereof.

Figure 10b shows the long-member configured with the seat-belt anchorage bracket in accordance with the present invention in a perspective view away from the other end thereof.

Figure 10c shows an enlarged partial view of the long-member configured with the reinforcement plate and seat-belt anchorage bracket in accordance with the present invention fixed on the long-member.

Figure 10d shows the long-member configured with the reinforcement plate configured in accordance with the present invention.

Figure 10e shows the seat-belt anchorage bracket in accordance with the present invention with spot welds loaded under shear below loading points.

Figure 11a shows the seat-belt anchorage bracket in accordance with the present invention depicting its typical surface of development.

Figure 11b to 11e show different views of the seat-belt anchorage bracket in accordance with the present invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1a shows the long-member LM configured with seat-belt anchorage bracket B in accordance with the present invention. The longitudinal axis of the long-member LM is in the vehicle longitudinal axis direction VLAD and the bracket is fixed on the long-member LM in an oblique axis direction OAD, whereas the bracket show orientation towards load direction OLD which is perpendicular to the oblique axis direction OAD.

Figure 1b shows a bracket B placed in an oblique direction L (along red arrow) on the long-member LM for making the cross-section parallel to the axial loading direction and the spots loaded in shear in accordance with the present invention. The rotation is eliminated by simple orientation of the bracket in the direction of resultant pull-load acting on the anchorage point, which can be seen from at least one of the vehicle co-ordinate axis. The spots are stronger in shear, this present invention makes use of this simple property and places the bracket such that the resultant seat belt anchorage force loads the spot welds in shear. The embossed portion of the long-member reinforcement LMR and weld nut WN with more bearing area is configured to distribute the load along the vertical wall (thickness), both of which are in tension and in turn they substantially reduce any local strain developed therein.

Figure 2 shows a closed cross-section of the bracket structure along the section line A – A depicted in Figure 1b, which is fixed adjacent the long-member wall LMW. The figure depicts faces of the seat-belt anchorage brackets B; long-members 30, 40 of the BIW fixed on the vehicle under body, profiled long-member reinforcement plate 50; rear-floors 60, 70 of BIW as well as a weld-nut 80. The inner and outer panel are spot welded to the vehicle under body. The closed cross-section gives better strength performance in terms of seat belt anchorage. The embossed area acts as a bearing surface to prevent any stress concentration. The load transfer path passes through the emboss on the bracket and the bearing area of the weld-nut 80 towards the vertical walls of the bracket, which in turn loads the spots welds. The emboss helps in preventing the development of local strains by increasing the load bearing area. Once loaded, the face 10 of bracket B undergoes tension loading (i.e. spot welds 52, 54 in Figure 10e), while the spot welds undergo compressive loading, thereby prevents the unwanted rotation and buckling phenomena of bracket B. Spot weld face 20 and long-member 30 of bracket B undergo tension loading, which is minimizes by providing (additional flanges) shear loaded spot weld 50 on long-member 30 (Figure 10e).

Figure 3 shows the vehicular seat schematically depicting the sear-belt anchorage assembly. The rear floor has a seat anchorage bracket B depicted on the right side thereof, through which the seat-belt SB is attached.

Figure 4 shows an enlarged view of the long-member LM fitted with the seat-belt anchorage bracket B configured in accordance with the present invention having side flanges SF for preventing any buckling in transverse direction during loading. The dashed rectangular area depicts the flanges of the bracket, which are loaded along the axis thereof. This prevents the section collapse and also helps in reducing the overall displacement of the anchorage bolt. This in turn reduces the local strains developed in the rear floor at the anchorage locations thereby completely eliminating possibility of material tear at the anchorages.

Figure 5a shows the bracket in the initial state thereof without any loading.

Figure 5b shows another view of the bracket in the initial state thereof, with no load depicted on the bracket.

Figure 5c shows the long-member with no load depicted thereon.

Figure 6a shows the load distribution in the bracket at half load condition, wherein the embossed area of the bracket has started (marked in red) taking the load.

Figure 6b shows another view of the load distribution occurring in the bracket at half load condition. Here also, the embossed area of the bracket has started (marked in red) taking the load.

Figure 6c shows the load distribution in the long-member at half load condition, which also depicts the embossed area of the bracket having started (marked in red) taking the load.

Figure 7a shows the load distribution in the bracket at full load condition, wherein load is transferred (marked in red) to the underbody through joinery.

Figure 7b shows another view of the load distribution in the bracket at full load condition. Here also, the load is being transferred (marked in red) to the underbody through the joinery.

Figure 7c shows the load distribution in the long-member at full load condition, which also the load is being transferred (marked in red) to the underbody through the joinery.

Figure 8a shows an enlarged side view respectively of the seat-belt anchorage assembly configured in accordance with the present invention.

Figure 8b shows an enlarged top view respectively of the seat-belt anchorage assembly configured in accordance with the present invention.

Figure 9a shows the rear floor of the seat structure configured in accordance with the present invention for supporting the passenger and/or luggage load.

Figure 9b shows the central floor of the seat structure configured in accordance with the present invention for supporting the passenger load.
Figure 9c shows the cross-member for the rear floor of the seat structure configured in accordance with the present invention to increase the torsional stiffness of Body-In-White (BIW).

Figure 9d shows the long-member of the seat structure configured in accordance with the present invention to increase the bending stiffness of Body-In-White (BIW) and to support in a rear crash.

Figure 9e shows the long-member reinforcement bracket of the seat structure configured in accordance with the present invention to increase the bending stiffness of Body-In-White (BIW) and to support in a rear crash.

Figure 9f shows the seat-belt anchorage bracket for the seat structure for supporting seat-belt anchorage loads made according to the present invention.

Figure 10a the long-member configured with the seat-belt anchorage bracket in accordance with the present invention in a view from one end thereof.

Figure 10b shows the long-member configured with a seat-belt anchorage bracket according to the invention in a view away from another end thereof.

Figure 10c shows an enlarged partial of the long-member configured with the reinforcement plate and seat-belt anchorage bracket in accordance with the present invention fixed on the long-member by means of spot welds in order to be loaded under shear below the loading points (Figure 11a).

Figure 10d shows the long-member configured with reinforcement plate LMR in accordance with the present invention. The spot welds 50 depicted herein are loaded under shear below the loading points, whereas spot welds 52, 54 are loaded under tension above and below the loading points respectively.

Figure 10e shows the seat-belt anchorage bracket B in accordance with the present invention, depicting the spot welds 50 depicted herein loaded under shear below the loading points.
Figure 11a shows the seat-belt anchorage bracket in accordance with the present invention depicting its typical surface of development

Figure 11b shows front view of the seat-belt anchorage bracket in accordance with the present invention.

Figure 11c shows a rear view of the seat-belt anchorage bracket in accordance with the present invention.

Figure 11d shows a top view of the seat-belt anchorage bracket in accordance with the present invention.

Figure 11e shows a side view of the seat-belt anchorage bracket in accordance with the present invention.

WORKING OF THE INVENTION:

The present invention relates to a novel concept for configuring a seat-belt bracket structure for vehicular seat-belt anchorages placed in the body structure (BIW). This concept eliminates the undesired twisting or torsional loads acting on the bracket structure and thus, reduces the usually long time and cost involved in design iteration and validation thereof. The zones and the strength of proof loads for the seat-belt anchorages defined under ECE R14 or its Indian equivalent AIS 15 are suitably met to increase the reliability of seat-belt anchorage design. The bracket design also complies with the mandatory prescribed limits in terms of positioning, orientation and joinery with the nearby BIW structure.

In contrast to the conventional bracket designs having two directional angular loads acting on the bracket which lead to undesired turning and twisting of the bracket during loading thereof, the inventive design eliminates the rotation of the bracket by simple orientation of the bracket in the direction of resultant pull load acting on the anchorage point, which can also be seen from at least one of the vehicle co-ordinate axis.
The concept also showcases that anchorage bracket joinery in terms of weld spot and flange design influencing a better behaviour of the seat-belt anchorage structure. Moreover, the inventive bracket structure can also be extended for mounting child restraint system namely, ISO FIX bracket, which can be bolted.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The seat-belt anchorage system configured in accordance with the present invention has the following advantages:

• Critical spots are loaded in shear.

• Time and cost involved with design iteration and validation is reduced.

• Increases reliability of design to meet stringent regulatory requirements.

• Seat-belt mounting can also be configured to act as ISO-FIX anchorage for child restraint system.

• Offers ease of variant management.

• Underbody joinery takes the load.

• Placement of the bracket eliminates the rotation of the bracket.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.
The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification.

Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.