Thin, double-wall molded seat frame system

Abstract

A seat frame for a vehicle or other seating comprises a seat back and a seat pan formed of molded double wall members having thin, substantially closed exterior walls and a substantially open interior. The exterior walls include front and back sections having a cavity therebetween, secured together to form a hollow, box beam type of structure. Integrally formed, spaced cup-shaped standoffs extend between the front and back sections between side walls thereof and provide internal reinforcement of the seat member between the side walls. The seat back includes a cavity for a seat back reinforcement member for either a restraint or non-restraint seat.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application is based on and claims the benefit of the filing date of co-pending U.S. Provisional Patent Application Ser. No. 61 / 237,926, entitled Thin, Double-Wall Molded Seat Frame System and filed on Oct. 4, 2000, by Patrick M. Glance and Bradley M. Glance, the disclosure of which is incorporated here by reference.BACKGROUND OF THE INVENTION [0002] The invention relates to vehicular seating generally and more particularly to a new vehicular seat frame. [0003] Today automotive seat frames, for example, are constructed from a number of materials and manufacturing technologies. Most seat frames and seat backs are fabricated from steel tubing. Front bucket seat pans (a lower seat frame utilized to mount a seat lower cushion) are commonly stamped steel with a steel seat spring suspension, although a technology limitation of steel seating frames is their large mass. Some seat frames utilize aluminum or magnesium, which has lighter mas...

AI Technical Summary

Benefits of technology

[0043] Another advantage of the present invention is that the seat frame pan and seat back are formed in two cavity halves, which are molded together to form a closed box section. It is desired that the walls of the two cavities, in each case, are relatively thin (typically about 1 mm) and hence flexible, with internal, molded standoffs reinforcing the outer walls when the two cavities are joined together. Notwithstanding the extremely thin walls, the seat frame pan and seat back provide good structural performance.

[0044] The seat frame pan and seat back can be formed from a number of different manufacturing processes, such as injection molding, twin sheet vacuum forming, vacuum die casting, casting, or compression molding. The seat frame pan may be formed of a number of different materials, such as high density polyethylene, polypropylene, acrylonitrile butadiene styrene, polycarbonate, sheet molding compound, PBT, PET, or metal such as magnesium, zinc alloy, or aluminum. Talc filled HDPE is typical. The seat back can be made of comparable materials.

[0045] As shown in FIG. 10, the formation of the seat back in two sections also facilitates incorporation of the reinforcement structure formed of metal. In such a case, the reinforcement cavity 20 can be formed between the front and back sections, with the reinforcement member in the form of tower 18 or 24 being positioned between the front and back sections before the back sections are welded or bonded together. The tower and other similar metal members for attachment or other purposes can thus be incorporated into the seat frame or seat back during the manufacturing process, thus facilitating attachment of the seat frame assembly to a vehicle. It should be understood that the reinforcement tower or other reinforcement member does not have to be inserted in the mold cavity prior to joining the two molded halves. Instead, the reinforcement member could be inserted after the product has been formed and attached by interference fit, adhesion, or mechanical fasteners. Even when the tower is inserted into the mold when the sections are attached together, such fasteners may be used to maintain the position of the tower in the seat back or the like.

[0046] It will be understood by one having ordinary skill in the art and by those who practice the invention, that various modifications and improvements may be made without departing from the spirit of the disclosed concept. Various relational terms, including left, right, front, back, top, and bottom, for example, are used in the

Problems solved by technology

Front bucket seat pans (a lower seat frame utilized to mount a seat lower cushion) are commonly stamped steel with a steel seat spring suspension, although a technology limitation of steel seating frames is their large mass.

Some seat frames utilize aluminum or magnesium, which has lighter mass, but is more expensive.

A technology limitation of molded seat frames is their relatively large molding thickness, typically about 3 mm with ranges from about 6 to about 2 mm.

The large molding thickness results in a slow molding cycle time, and greater material usage, which directly results in a higher seat frame cost.

This is a technology limitation and natural consequence of plastic seat frames.

These technology limitations have resulted in steel seat back frames weighing 6 to 8 pounds and costing $8 to $12, while steel bucket seat frame assemblies weigh between 4 to 6 pounds, and cost between $4 to $6.

Molded seat frames are typically expensive compared to steel frames, but are utilized for specialty, niche applications where the molded surface doubles as a styling show surface, a load floor, or is utilized to reduce mass in conjunction with metal reinforcement.

Molded seat frames often have a lower mass than their steel counterparts, at a higher cost.

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