Stock material or miscellaneous articles – Hollow or container type article – Polymer or resin containing
Reexamination Certificate
2001-11-08
2004-08-17
Pyon, Harold (Department: 1772)
Stock material or miscellaneous articles
Hollow or container type article
Polymer or resin containing
C428S071000, C428S120000, C428S122000, C428S137000, C428S036500, C428S035800, C052S793100, C293S109000, C293S132000, C296S182100, C296S205000
Reexamination Certificate
active
06777049
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to reinforcing materials and in particular to reinforcing materials that can be provided in hollow cross-sectional members particularly to provide reinforcement to improve the structural integrity of articles.
BACKGROUND OF THE INVENTION
The trends in motor vehicle design are towards lighter vehicles to improve fuel consumption. At the same time, auto manufacturers continue to demand more rigorous structural performance standards. The use of lighter materials such as aluminum to produce the hollow cross-sectional members that are used as vehicle sub frames has lead to the desire for additional reinforcement. There is a need for reinforcement in various locations in the vehicle structure including the sub frame and upper structure and the form of reinforcement required can vary from one location in the vehicle to another and from vehicle to vehicle. The present invention therefore improves the strength of vehicles structures made from existing materials and enables vehicle structures based on lighter materials to satisfy safety requirements they are otherwise unable to satisfy.
The electrocoat process used in vehicle manufacture is a process in which the vehicle structure is passed through a bath of anticorrosion fluid and the vehicle is used as an electrode whereby an anticorrosion coating is deposited from the fluid onto the vehicle structure by electrolysis. The invention further provides a system whereby reinforcement can be provided whilst ensuring effective provision of an anti-corrosion coating on the inner surface of the hollow cross-sectional member by the electrocoat process.
There are four main types of applications where structural reinforcement is desired in vehicles. In one, control over vehicle body deformation is attractive for assisting in accident management. In another, it is desirable for increased energy absorption to enhance performance after yield of a structure. The reduction of flexing or body movement in the vehicle structure particular to improve durability and reduce stress effects and point mobility issues requiring the reduction of resonance by the provision of stiffening. The need for reinforcement is present irrespective of the materials that are used to produce the vehicle structure and the need varies from material to material according to the nature of the reinforcement that is being provided. The reinforcing parts can also reduce the noise created by the motion of a vehicle by having a sound deadening effect as a result of blocking air paths in cavities.
It is known to provide longitudinal reinforcing structures within the hollow cross sections of vehicles. For example, PCT Publication WO97/43501 provides a beam, which can be mounted within the cross section to provide reinforcement along one axis in a hollow structure. The beam is provided with an expandable adhesive on two surfaces, which can be foamed upon heating to bond the beam to two opposed walls of the cross section. This technique is not suitable for use in an electrocoat process commonly encountered in automotive applications. Furthermore, the beam will only provide significant reinforcement along the axis of the beam. In WO97/43501 the beam with foamable material on opposed surfaces is placed in the cavity and subsequently foamed under the action of heat. This will result in uneven foaming and to non-uniform foam structures since on the underside the foam must raise the weight of the beam whereas expansion on the topside is free.
It is also known to provide foamable plastic mouldings within the hollow cross sections which can be foamed upon application of heat, such as is provided by the baking step in the electrocoat process, to provide a foamed baffle that fills the cross-section to provide sound adsorption. Such systems are described in European patent applications 0383498 and 0611778. The foam baffle provides sound deadening and vibration resistance. In these systems the entire insert is foamable and it is proposed that the foamable material be chosen so that it will foam during the baking process, which follows the electrocoat process typically used in vehicle manufacture to provide resistance to metal corrosion. The materials of these patents are not however reinforcing materials but are used to provide acoustic baffles and seals.
In the electrocoat process a vehicle structure is immersed in a bath of coating fluid from which an anticorrosion coating is deposited on the metal by electrolysis. The vehicle metal structure is subsequently heated to bake the coating on the metal. The electrocoat process is typically applied to complete vehicle structures in which hollow sections have been capped. Accordingly reinforcing structures are preferably provided within hollow sections prior to the electrocoat. It is therefore important that the reinforcing structure have minimal impact on the operation and efficiency of the electrocoat process.
Where reinforcing materials have been provided they have either been stuck to the metal structure prior to subjecting the vehicle structure to the electrocoat process or have been provided after the electrocoat process. The former technique has the problem that it is not possible to perform the electrocoat over the entire surface, which can lead to local areas of corrosion. The latter technique is cumbersome and requires the provision of fastening means after electrocoating, which can damage the electrocoat and again lead to local areas of corrosion.
There is therefore a need to provide structural reinforcement for the hollow cross-sections of vehicles, which is easily supplied, works well within the bounds of the electrocoat process and provides effective reinforcement to the vehicle both during operation and as crash protection.
The present invention therefore provides a structural reinforcement for a hollow member comprising a rigid reinforcing member having a shape that substantially conforms to the cross section of the section of the hollow member to be reinforced with an expandable adhesive material over at least a portion of the surface of said rigid reinforcing member sufficient to bond the reinforcing member to at least two non parallel internal surfaces of the structure.
In one aspect of the invention, the dimensions of the rigid reinforcing member and the thickness and nature of the expandable material are important to the achievement of the desired structural reinforcement. The exterior shape of the reinforcing member should conform substantially to the cross section of the section of the structure it is designed to reinforce. The shape may vary along the length of the reinforcing member as the dimensions of the cross section of the structure change. The size of the reinforcing member including the expandable adhesive material should be such that there is a small clearance between the extremity of the reinforcing member and the interior walls of the structure it is to be reinforced (e.g., the frame of the vehicle) to allow for passage of the electrocoat fluid. Preferably, the reinforcing member has a cellular, honeycomb or ribbed internal structure to provide reinforcement along several different axes.
In a preferred embodiment the structural reinforcing member is provided with small lugs, which enable it to stand away from the interior walls of the sections of the structure to be reinforced. In this way fastening devices are not required and the area of contact between the structural reinforcing member and the interior walls of the structure is minimized. In a preferred embodiment, the clearance between the extremity of the reinforcing member and the interior walls of the structure (e.g., frame of the vehicle) must be wide enough to enable the liquid used in any coating (such as the electrocoat bath) to flow between the reinforcing member and the interior walls of the sections of the structure in sufficient quantity to enable an effective coating (e.g., anti-corrosion coating) to be deposited. On the other hand, the clearance must not be too wide since this can result in a lack of
Bieber Serge
Bourdin Jean Philippe
Gall Eric Le
Sheldon Simon
Dobrusin & Thennisch PC
L&L Products Inc.
Miggins Michael C.
Pyon Harold
LandOfFree
Structural foam does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Structural foam, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structural foam will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3339495