DESC:Field of the invention:

The present invention relates to a stepping board for automotive bodies and more particularly, to a composite vehicular running board assembly.

Background of the invention:

Vehicular running boards are presently made of formed metal sheets which are assembled on a bracket to mount on a body. The extensive use of steel increases weight of the running board and hence, of the vehicle thereby resulting in a decrease in the fuel economy of the vehicle. Hence, the weight of the running board is required to be reduced in order to achieve better fuel economy for meeting fuel economy standards and to compensate for higher fuel prices.

Several attempts have been made in the prior art to reduce weight of the running board on the vehicle. For example, United States Patent Numbers US 1745790, US 6997469 B2, US 6412799 B1 and US 2005/0012295 A1 and European Patent Number EP 1071580 B1 discloses different types of structural running boards made up of composite material technology. However, none of the patent resulted in substantial reduction in weight of the running board.

Accordingly, there is a need for a running board that enables reduction of the overall weight of a vehicle while extending the requisite structural requirement.

Objects of the invention:

An object of the present invention is to provide a light weight, rigid and composite vehicular running board assembly that reduces weight and increases fuel efficiency of a vehicle.
Another object of the present invention is to provide the composite vehicular running board assembly having increased durability to bear the load produced by two people stepping inside the vehicle at a time.

Summary of the invention:

Accordingly, the present invention provides a composite vehicular running board assembly. The composite vehicular running board assembly comprises a reinforcement member, a flange and at least two paddings. The reinforcement member is made up of at least two first layers and at least one second layer. The at least one second layer is sandwiched between the at least two first layers. Each first layer is made of a glass fiber mat. The second layer is made of a perforated flexible metal sheet. The layers are bonded together by molding with a resin matrix. The at least one second layer is capable of automatically bending at a groove to acquire a desired shape.

The reinforcement member includes an average concentration zone and a high concentration zone of the layers. The reinforcement member is mounted on a vehicle body by a plurality of brackets. The flange is fixed on an outer edge of the reinforcement member. The flange includes a higher concentration of the at least two first layers to take care of abuse load. The at least two paddings are fixed on the reinforcement member for non-skid application.

Brief description of the drawings:

Other features as well as the advantages of the invention will be clear from the following description.
In the appended drawings:
Figure 1 shows a composite vehicular running board assembly, in accordance with the present invention;

Figure 2 illustrates shapes of different layers of a reinforcement member of the composite vehicular running board assembly of figure 1;

Figure 3 illustrates an area covered by the different layers of the reinforcement member of the composite vehicular running board assembly of figure 1 along section A-A; and

Figure 4 illustrates sequencing and loading of the different layers in the part of the reinforcement member of the composite vehicular running board assembly of figure 1 along section A-A.

Detailed description of the embodiments:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides an improved form of a composite vehicular running board assembly. The composite vehicular running board assembly of the present invention is rigid, durable and light in weight and hence, reduces the overall weight as well as increases fuel efficiency of the vehicle.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1-4, a composite vehicular running board assembly (100) (herein after ‘the assembly (100)’), in accordance with the present invention is shown. Specifically, the assembly (100) is manufactured by a basic process of injection molding, particularly reaction injection molding or structural reaction injection molding. However, it is understood that any other suitable technique can be used for manufacturing the assembly (100). The assembly (100) comprises a reinforcement structure/member (30), a flange (50) and at least two paddings (70) as shown in figure 1.

The reinforcement member (30) shown by dotted line in figure 1 is equally distributed on a horizontal platform (not numbered) for mounting on a vehicle body (not shown) that defines a compartment (not shown). In an embodiment, the reinforcement member (30) is mounted on a vehicle BIW body by a plurality of brackets (10) such that each bracket (not numbered) of the plurality of brackets (10) placed on the reinforcement member (30) are separated by a distance not exceeding 536 mm.

Specifically, the reinforcement member (30) is a molded composite running board made up of at least two first layers (20) (herein after ‘the first layers (20)’) and at least one second layer (25) (herein after ‘the second layer (25)’). The first layers (20) are high strength layers made up of an especially loaded woven glass mat/fiber. The first layers (20) take care of abuse load. The second layer (25) is a non-stamped layer made up of a light perforated flexible metal sheet/film. The second layer (25) includes a plurality of circular holes (not numbered) perforated thereon. In an embodiment, the second layer (25) is 1.2 mm thick. The shapes of the layers (20, 25) are illustrated in figure 2. The second layer (25) being flexible automatically takes up a desired shape at a groove (22) in a tool (not shown) without appearing on an upper surface of the reinforcement member (30) as shown in figure 3. The tool is used to give desired shape and/or profile to the product in a tooling/ manufacturing process of the composite products.

The first layer (20) is connected on each side (not numbered) of the second layer (25) thereby sandwiching the second layer (25) therebetween. The first layer (20) and the second layer (25) are bonded together by a resin matrix (not shown). The reinforcement member (30) is formed to have at least one average concentration zone and at least one high concentration zone of the layers (20, 25) as shown in figure 3 by molding of the resin matrix together with the glass mat and the metal sheet, each being used in variable concentrations. Figure 4 illustrates sequencing and loading of the layers (20, 25) in a part of the reinforcement member (30).

The flange (50) is fixed on an outer edge (not numbered) of the reinforcement member (30). The flange (50) serves as a load bearing area during real world usage. The proportion and thickness of the first layers (20) at the flange (50) area is higher to take care of the abuse load.

The at least two paddings (70) are mounted on the reinforcement member (30). In an embodiment, the at least two paddings (70) are soft pads glued or assembled with positive mounting to the reinforcement member (30) for non-skid application.

Validation Results of the assembly (100)

When a load of at least 115 Kgs is applied on a footstep at two centre of a door for 1, 00,000 cycles, following results are observed:

Advantages of the invention:

1. The assembly (100) being rigid and light weight increases fuel efficiency of the vehicle.
2. The assembly (100), a liquid resin molded hybrid running board is economical to manufacture and eliminates stamping process for metal sheet reinforcement.
3. The reinforcement member (30) is manufactured in the structural reaction injection moldings standardized as per design requirements, layer sequence and structural requirements.
4. The reinforcement member (30) prevents undesirable deformation of light weight vehicular door under critical loading and environmental conditions.
5. The reinforcement member (30) has better structural performance while maintaining less weight.
6. The circular holes perforated on the second layer (25) gives light weight and flexibility to adopt any/ required shape and thus, eliminates the need of forming process for metal reinforcement.
7. Increased glass percentage and specially structured glass mat in the first layers (20) at flange area is effective against the abuse load on the flange (50).
8. The assembly (100) is improved in design as the second layer (25) is sandwiched between the first layers (20) and does not appear on the upper surface.
9. The second layer (25) is cut as per required shape and no forming required. The second layer (25) is flexible and automatically takes the shape by bending at the groove (22).
10. Even force distribution from horizontal platform and reinforcement member (30) sequence structure to the plurality of brackets (10).
11. Stylish form of the assembly (100) with improved look. The present invention allows molding of integrated and stylish form of the running boards with improved look.
12. Bracket spacing not exceeding 536 mm which is higher than generally used distance in footrest, still capable of withstanding the load without failure.
13. The assembly (100) is durable with following load capability at different place: Passenger at the two side door centre normally 115 kg each one minimum deflection 10 mm and permanent set less than 5 mm.
14. The at least two paddings (70) is fixed on final finished surface of the reinforcement member (30) to avoid any defects including visual defects due to uneven boundary formation of two different layers (20, 25).

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.

,CLAIMS:We Claim:

1. A composite vehicular running board assembly (100) comprising:
• a reinforcement member (30) made up of at least two first layers (20) and
at least one second layer (25) sandwiched between the at least two first layers (20), each first layer being made of a glass fiber mat, the second layer (25) being made of a perforated flexible metal sheet, the layers (20, 25) bonded together with a resin matrix, the at least one second layer (25) being capable of automatically bending at a groove (22) to acquire a desired shape;
• a flange (50) fixed on an outer edge of the reinforcement member (30), the
flange (50) having a higher concentration of the at least two first layers (20) to take care of abuse load; and
• at least two paddings (70) fixed on the reinforcement member (30) for
non-skid application.

2. The composite vehicular running board assembly (100) as claimed in claim 1, wherein the reinforcement member (30) includes an average concentration zone and a high concentration zone of the layers (20, 25).

3. The composite vehicular running board assembly (100) as claimed in claim 1, wherein the reinforcement member (30) is mounted on a vehicle body by a plurality of brackets (10).

4. The composite vehicular running board assembly (100) as claimed in claim 1, wherein the reinforcement member (30) is formed by molding the layers (20, 25) with the resin matrix.