Metal working – Method of mechanical manufacture – Structural member making
Reexamination Certificate
1998-06-23
2001-05-22
Rosenbaum, T Cuda (Department: 3726)
Metal working
Method of mechanical manufacture
Structural member making
C029S897200, C029S897350, C029S402090, C029S402180, C029S530000, C052S309140, C052S309150, C052S749100, C052S749100
Reexamination Certificate
active
06233826
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to the reinforcement of hollow structural members and more specifically deals with reinforcement of structures having enclosed regions that present special access problems.
BACKGROUND OF THE INVENTION
In recent years, a number of factors have necessitated fundamental changes in the approach to automotive structural design. These include the need to meet ever-increasing impact resistance and fuel economy standards and the need to produce a competitively priced vehicle in a global marketplace. At times, these requirements are seemingly at odds with one another. For example, impact resistance can in most cases be achieved simply by increasing steel thickness or through the use of high strength steels. These approaches, however, generally increase vehicle weight and/or cost. Although light-weight resins are available which can be used to fill entire hollow cavities of structural members to provide greater strength, these materials are expensive and thus their use in great quantities undesirably increases vehicle cost.
The present inventor has pioneered a novel approach to structural part reinforcement through localized reinforcement of critical regions using microsphere-filled thermally expandable resins, such as: a composite door beam which has a resin-based core that occupies not more than one-third of the bore of a metal tube; a hollow laminate beam characterized by high stiffness-to-mass ratio and having an outer portion which is separated from an inner tube by a thin layer of structural foam, a W-shaped carrier insert reinforcement which carries a foam body for use in reinforcing a hollow beam; a bulkhead that utilizes a thermally expandable foam to provide localized reinforcement of a rail for the attachment of an engine cradle or the like.
Although these techniques are well suited for a number of applications, there exists a need for localized reinforcement of regions having special access problems. More specifically, in a number of hollow structural parts the member has an enclosed region or space which is located some distance from the opening of the space and is difficult to reach due to a curvature or bend in the member. In some instances the member and the channel which it defines have an irregular geometry that makes access to a particular internal region difficult. Of course, in some instances it may be possible to simply fill the entire structure with a liquid resin which is then cured, but as stated above, this approach may be prohibitively expense in a number of applications. Accordingly, there is a need for an alternative method of providing localized reinforcement of such parts. The present invention provides a solution to this problem.
It is an object of the present invention to provide a method of providing a local reinforcement in a region of a hollow structural part which is difficult to reach using conventional techniques.
It is a further object of the present invention to provide a method of introducing a localized resin reinforcement in a structural part where the region to be reinforced is beyond a curvature in a channel.
It is still a further object of the present invention to provide a method of centralizing a resin reinforcement in a hollow structural part in a region which is difficult to access.
SUMMARY OF THE INVENTION
In one aspect the present invention provides a method of reinforcing a part in a localized region. The method includes the steps of providing a flexible member having a length substantially greater than its width; covering at least a portion of the flexible member with a thermally expandable resin; and inserting the flexible member into the cavity of a hollow structural part. The insertion step includes the step of bending the flexible member to accommodate the geometry of the part cavity. The resin is then thermally expanded such that the resin is bonded to the structural part. In this manner, localized reinforcement can be achieved for any number of parts whose internal geometry would make it difficult or impossible to reinforce using conventional techniques.
In one aspect, the flexible member is a tube around which the resin is applied as a layer or coating. The resin-coated tube is then inserted in the structural part and bends as pressure is applied such that it can be fed into the part cavity, i.e. it conforms to the desired shape as it is inserted into the part.
In one aspect, the resin includes a blowing agent and glass microspheres. After the flexible member is in place in the part, the part is heated, for example after installation in a motor vehicle, to a temperature sufficient to activate the blowing agent and thermally expand the resin. As the resin expands it bonds to the inner walls of the part forming a tube-in-tube type structure with high strength characteristics.
In one aspect, the thermally expanded resin includes, in parts by weight, from about 40% to about 80% resin, from about 10% to about 50% microspheres, from about 0.5% to about 5% blowing agent, from about 1% to about 15% filler, from about 0.5% to about 2% accelerator and from about 1% to about 8% curing agent.
In still another aspect, the flexible member includes one or more stand-offs which space it from the inner walls of the structural part.
These and other aspects, features and objects of the invention will be more fully described in the following detailed description of the preferred embodiments of the invention with reference to the drawings.
REFERENCES:
patent: Re. 30802 (1981-11-01), Rogers, Jr.
patent: Re. 34978 (1995-06-01), Adams et al.
patent: 1993307 (1935-03-01), Nicholson
patent: 3123170 (1964-03-01), Bryant
patent: 3493257 (1970-02-01), Fitzgerald et al.
patent: 4090734 (1978-05-01), Iami et al.
patent: 4186162 (1980-01-01), Daley
patent: 4238540 (1980-12-01), Yates et al.
patent: 4397490 (1983-08-01), Evans
patent: 4436120 (1984-03-01), Josien et al.
patent: 4484386 (1984-11-01), Stonitsch
patent: 4559274 (1985-12-01), Kloppe et al.
patent: 4610836 (1986-09-01), Wycech
patent: 4640150 (1987-02-01), Kobayashi et al.
patent: 4751249 (1988-06-01), Wycech
patent: 4783890 (1988-11-01), Gaudin
patent: 4836516 (1989-06-01), Wycech
patent: 4853270 (1989-08-01), Wycech
patent: 4861097 (1989-08-01), Wycech
patent: 4901500 (1990-02-01), Wycech
patent: 4908930 (1990-03-01), Wycech
patent: 4922596 (1990-05-01), Wycech
patent: 4923902 (1990-05-01), Wycech
patent: 4936004 (1990-06-01), Vaughn
patent: 4978562 (1990-12-01), Wycech
patent: 4995545 (1991-02-01), Wycech
patent: 5040283 (1991-08-01), Pelgrom
patent: 5122398 (1992-06-01), Seiler et al.
patent: 5124186 (1992-06-01), Wycech
patent: 5194199 (1993-03-01), Thum
patent: 5199463 (1993-04-01), Lippiatt
patent: 5242637 (1993-09-01), Inoue et al.
patent: 5255487 (1993-10-01), Weiting et al.
patent: 5474721 (1995-12-01), Stevens
patent: 5575526 (1996-11-01), Wycech
patent: 5665295 (1997-09-01), Takamoto et al.
patent: 5884960 (1999-03-01), Wycech
patent: 5885494 (1999-03-01), Venkataraman et al.
patent: 29 19 049A (1980-11-01), None
patent: 90 11 147.8 (1990-12-01), None
patent: 4203460 (1992-08-01), None
patent: 93 20 333.0 (1994-07-01), None
patent: 0 061 131 (1982-09-01), None
patent: 0 414 302 A1 (1991-02-01), None
patent: 0 453 777 A2 (1991-10-01), None
patent: 628868 (1947-03-01), None
patent: 2061 196 (1981-05-01), None
patent: 2197 267 (1988-05-01), None
patent: 01069308 (1989-03-01), None
patent: 01069309 (1989-03-01), None
patent: 02206537 (1990-08-01), None
patent: 5389920 (1993-02-01), None
patent: WO 89/06595 (1989-07-01), None
patent: WO 93/05103 (1993-03-01), None
Harper Stephen D.
Jaeschke Wayne C.
Nguyen Trinh
Pezzner Harold
Rosenbaum T Cuda
LandOfFree
Method for reinforcing structural members does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for reinforcing structural members, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for reinforcing structural members will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497600