Spring devices – Resilient shock or vibration absorber – Nonmetallic – resilient element
Reexamination Certificate
1999-03-12
2001-05-29
Schwartz, Chris (Department: 3613)
Spring devices
Resilient shock or vibration absorber
Nonmetallic, resilient element
C267S293000
Reexamination Certificate
active
06237903
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to bushing assemblies, and more particularly to bushing assemblies for retaining suspension control arms of motor vehicles.
2. Disclosure Information
Obtaining the optimal ride and handling characteristics of a motor vehicle often requires that suspension bushings have different radial and axial spring rates. Preferred handling characteristics often demand high radial spring rates. Conversely, noise, vibration, and harshness, NVH, and ride characteristics require low axial spring rates in the bushing. Typically, suspension bushings employ elastomers in which the radial and axial spring rates are coupled, therefore requiring a compromise in the selection between preferred handling characteristics and preferred NVH and ride characteristics. Attempts to overcome this compromise include the use of voided bushings, permitting varying degrees of stiffness by removing elastomeric material in specific areas of the bushing. While the voided bushing does allow for unique spring rates, it does not allow for complete decoupling of the axial and radial spring rates.
It would therefore be desirable to provide a bushing which is capable of having axial and radial spring rates that are decoupled, allowing more precise tuning for improved handling, NVH, and ride characteristics.
SUMMARY OF THE INVENTION
According to the present invention, a bushing apparatus has been discovered for interconnecting two members and allowing relative motion therebetween. The bushing apparatus includes an inner cylindrical member having a first outer surface and first and second ends. First and second stops which project radially outward from the first outer surface of the inner cylindrical member are positioned at the first and second ends, respectively. An outer cylindrical member having a first inner surface is arranged coaxially with the inner cylindrical member. A bearing member having second inner and outer surfaces is interposed coaxially between the inner and outer cylindrical members. The second inner surface of the bearing member is cylindrical and slidable relative to the first outer surface of the inner cylindrical member. A first elastomeric member having third and fourth ends and a third inner surface is disposed coaxially with the inner cylindrical member. The third end of the first elastomeric member is adjacent to the first stop and the fourth end is adjacent to the bearing member. A second elastomeric member having fifth and sixth ends and a fourth inner surface is disposed coaxially with the inner cylindrical member. The fifth end of the second elastomeric member is adjacent to the second stop and the sixth end is adjacent to the bearing member. At least one of the first and second elastomeric members is unsecured to the bearing member.
It is an advantage of the present invention to provide decoupled axial and radial spring rates to allow the inner cylindrical member to move against at least one elastomeric member without compressing or stretching at least one other elastomeric member.
REFERENCES:
patent: 1827233 (1931-10-01), Hughes
patent: 1827267 (1931-10-01), Short
patent: 4139246 (1979-02-01), Mikoshiba et al.
patent: 4721326 (1988-01-01), Massos et al.
patent: 4809960 (1989-03-01), Kakimoto et al.
patent: 5058867 (1991-10-01), Hadano et al.
patent: 5439203 (1995-08-01), Hadano
patent: 5595452 (1997-01-01), Hill et al.
patent: 5820115 (1998-10-01), Stevenson et al.
Kmiec Daniel F.
Novak Stanley Jay
Brown Gregory P.
Ford Global Technologies Inc.
Schwartz Chris
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