Land vehicles: bodies and tops – Bodies – Structural detail
Reexamination Certificate
1998-09-25
2001-01-30
Dayoan, D. Glenn (Department: 3612)
Land vehicles: bodies and tops
Bodies
Structural detail
C296S156000
Reexamination Certificate
active
06179371
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to materials for applications such as walls in static structures and the like. More particularly, the invention relates to a wall for an over-the-road vehicle such as a vehicle of the general class known as recreational vehicles or “RVs.”
BACKGROUND OF THE INVENTION
For virtually any enclosed structure having one or more walls exposed to weather, it is important that the structure walls retain their watertight integrity. And for many types of structures, maintenance of the appearance of the wall is important. When the wall is part of a static structure, the techniques and materials which provide watertight integrity and attractive, long-lasting appearance are known. But when the wall is part of the driver- and passenger-enclosing body of a type of motor vehicle, the techniques and materials have been found less than satisfactory.
U.S. Pat. No. 4,082,882 (Weinstein et al.), U.S. Pat. No 4,491,362 (Kennedy) and U.S. Pat. No. 4,791,768 (Crean) all disclose products useful in making motor vehicle bodies of one type or another. The Weinstein et al. patent discloses a multi-layer structure said to be useful in making truck walls or the like. In one version of the structure, its layers include, from the exterior inwardly, sheet acrylic, general purpose resin, fiberglass, plywood, general purpose resin, and fiberglass.
The Kennedy patent discloses a fiberglass body for a Jeep vehicle. In an embodiment, only the inner and outer rigid shells are fiberglass. Such shells have what the patent calls “close foam” insulation material, e.g., styrofoam or urethane, between them.
The Crean patent discloses a composite structure for mobile applications such as motorized coaches. The structure includes what the patent calls a second subassembly which, from the exterior inwardly, includes fiberglass exterior sheathing, a glue layer, a first substrate made of foam laminated between paper, another glue layer, and a relatively thick layer of plywood.
Commonly, recreational vehicles have sidewalls made differently than any of the arrangements described in the above-mentioned patents. Such RV sidewalls include a sheet of a fiberglass product, the smooth “finished” surface of which is exposed to weather, road grit and the like. An exemplary product is FILON™ gel-coated, semi-rigid fiberglass-reinforced polyester resin material, about 0.045 to 0.06 inches thick, available from Kemlite Company, Joliet, Ill.
A sheet of lauan plywood is bonded to the interior surface of the fiberglass using moisture-cured urethane or polyurethane reactive hotmelt. In lieu of such plywood, the fiberglass may have bonded thereto a particle board made in Europe.
Lengths of rectangular aluminum tube are spaced along and adhere to the plywood or to the particle board, as the case may be. In the finished RV, the tubes are generally vertical and are spaced horizontally. Other tubes are mounted horizontally across the top and bottom of the vertical tubes. In preferred practice, the tubes form a welded frame.
A slab of styrofoam insulation is placed into each space between adjacent pairs of tubes and is also glued to the plywood or particle board. And when considered from the outside inwardly, styrofoam insulation is between the plywood and the interior wall visible to passengers.
A problem with this construction arises from the fact that as the RV moves along the road, it “flexes.” Moisture migrates inwardly, both through the wall/seal junction at resilient seals around doors and windows and, perhaps, at the junction of a side wall and another wall structure. Such moisture permeates the plywood layer, causing it to rot. Or, less likely, such moisture causes a failure in the adhesive used to make the plywood.
Significant moisture migration eventually evidences itself in a “wavy” or “bulgy” outer fiberglass surface and/or interior wall. In addition, the cellulosic fibers of the plywood may separate and in any event, the plywood retains moisture for a long period of time.
None of these eventualities is acceptable to the vehicle owner or, for that matter, to the manufacturer. As to the latter, an RV manufacturer may, in a single year, experience very-substantial warranty claims. Attending to such claims detracts from the main production effort and drives up costs.
Yet another characteristic of the aforedescribed vehicle wall construction relates to vehicle weight. Of course, any significant saving in vehicle weight translates into improved fuel economy, reduced tire wear and other advantageous results. As will become apparent, the invention helps achieve further weight reduction in the walls of recreational vehicles.
Yet another concern relating to existing RV wall construction is the diminishing availability of lauan plywood. Lauan is a rain forest product and if its use is not voluntarily diminished, perhaps markedly so, the exhaustion of the forest will force other approaches.
Still another concern relating to existing RV wall construction using the Europe-sourced particle board is that, to be given reasonable consideration by the seller, a buyer must order very substantial quantities. This ties up cash in inventory and, in view of the invention, is unnecessary. And delivery “lead times” are considerable.
A new motor vehicle wall product and related method which address characteristics and disadvantages of earlier products would be an important advance in this field of technology.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a new motor vehicle wall product and related method that address problems and shortcomings of the prior art.
Another object of the invention is to provide a new motor vehicle wall product and related method which are particularly well suited for production processes involving recreational vehicles.
Another object of the invention is to provide such a product and method which help maintain the weather integrity of a motor vehicle wall.
Yet another object of the invention is to provide such a product and method which help maintain the appearance of a motor vehicle wall.
Another object of the invention is to provide such a product and method which help reduce warranty and maintenance costs relating to recreational vehicles.
Another object of the invention is to provide such a product and method which help reduce vehicle weight.
Still another object of the invention is to provide such a product and method which diminish use of lauan wood.
Another object of the invention is to provide such a product and method which helps avoid tying up valuable cash resources in inventory. How these and other objects are accomplished will become apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
The invention involves a unique motor vehicle sidewall product made from existing constituents using, in significant part, existing equipment and providing remarkable, long-term benefits in RV construction. In general, the new product includes a fiberglass sheet having a first or exterior surface (exterior when the RV is completed) and a second, interior surface. A relatively thin bonding sheet adheres to the second surface and comprises between 25% and 60% resin and between 75% and 40% paper. While a sidewall with one such bonding sheet is serviceable, a highly preferred sidewall product has two such bonding sheets. A first bonding sheet adheres to the second surface of the fiberglass sheet and a second bonding sheet adheres to the second (interior) face of the first bonding sheet. And even more bonding sheets may be used.
In one preferred embodiment, the bonding sheet is a natural bonding sheet and comprises between 35% and 60% resin and between 65% and 40% kraft paper having interstices, thereby permitting the adhesive resin to penetrate the paper. The ideal natural bonding sheet comprises between 38% and 42% resin and between 62% and 58% paper. Such bonding sheet has first and second faces and the tensile strength of the sheet along the “Z” axis, i.e., along an axis generally perpendicular to the faces, is at least 200 p.
Dayoan D. Glenn
Fiberesin Industries, Inc.
Jansson, Shupe Bridge & Munger, Ltd.
Morrow Jason
LandOfFree
Motor vehicle wall product and related method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Motor vehicle wall product and related method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Motor vehicle wall product and related method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2470866