Brakes – Inertia of damping mass dissipates motion – Resiliently supported damping mass
Reexamination Certificate
1999-07-22
2001-04-17
Oberleitner, Robert J. (Department: 3613)
Brakes
Inertia of damping mass dissipates motion
Resiliently supported damping mass
C267S141200, C267S141400, C267S136000, C267S140120
Reexamination Certificate
active
06216833
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to vibration dampers and in particular to a damper for use in a vehicle and specifically to a damper for mounting in the vehicle seat to isolate resident frequencies imparted on the passenger's seats. Even more particularly the invention relates to such a vibration damper having an anti-rotational device to prevent excessive rotation of the damping mass due to non-translational vehicle inputs.
2. Background Information
Damping devices and in particular dynamic dampers, are currently used in many applications and in particular in the automobile industry for damping out various vibrations imparted on portions of the vehicle caused by the engine, tires and road conditions. One problem that exists is that vibrations which result from resonance frequencies are imparted on the passenger seats of minivans which eventually could cause discomfort to the passenger.
Various types of dampers have been used to dampen out unwanted vibrations on various structures. These are generally of the shear type dampers in which a mass is attached in some fashion to an elastomeric member wherein the elastomeric material is bonded directly to the mass with the elastomer acting in shear. These dampers are then attached in some fashion to the structure or vehicle for damping out the unwanted frequencies.
Other types of dampers use a bushing arrangement wherein an elastomer is bonded between inner and outer cylindrical members such as shown in U.S. Pat. No. 5,769,380 and 4,889,328. Various other dampers using an elastomer and a damping mass are shown in U.S. Pat. Nos. 4,580,666; 4,800,306; 3,419,111; 5,876,023; 5,876,024 and 5,799,930.
However, a problem that occurs in such dampers is that the dampers are prone to exhibit very erratic motion both translational and rotational caused by excessive rotation due to non-translational vehicle inputs.
None of these prior art dampers, especially those that have a suspended mass, have any type of anti-rotational device to limit the angular swing of the mass which reduces the effectiveness desired to be achieved thereby. Likewise, many of the prior art damping devices, especially those intended for use in a vehicle seat, are difficult to manufacture in an economical manner and in a size and weight acceptable for use in the automotive industry.
Therefore, the need exists for an improved vibration damper intended primarily for use in a vehicle seat, which is relatively easy and inexpensive to manufacture and which may include an anti-rotational device to avoid erratic motion of the damper.
SUMMARY OF THE INVENTION
Objectives of the invention include providing an improved vibration damper for suspending on a structure such as a vehicle seat, which has a bushing assembly formed by inner and outer coaxial metal sleeves with an intervening elastomeric member, with a mass being attached to the outer sleeve by a press fit engagement thereby eliminating the need to place the mass in a vulcanizing mold when the elastomeric member is vulcanized and secured to the inner and outer sleeves.
Still another objective of the invention is to provide such a vibration damper which includes an anti-rotational device to restrict rotational motion of the damper, preferably by use of a metal extension arm secured to the inner metal sleeve and extending between a pair of elastomeric nubs formed integrally with the elastomeric member of the bushing assembly.
A further objective of the invention is to provide such a vibration damper in which the size of the mass can be easily adjusted and changed for particular applications and then press fitted onto the inner sleeve of the bushing assembly thereby providing for a larger range of damping applications with less components.
Another objective of the invention is to provide such a vibration damper in which the elastomeric member can have various shapes to achieve different spring characteristics without affecting the primary size and shape of the inner and outer metal sleeves thereby providing increased versatility to the damper.
A further objective of the invention is to provide such a vibration damper in which the outer metal sleeve has an annular flange over which the elastomeric material extends so as to act as a bumper to prevent any excess motion of the damper in a direction which is perpendicular to the primary direction of motion.
A still further objective of the invention is to provide such a vibration damper whereby after molding the elastomeric member to the inner and outer metal sleeves the bushing assembly is press fitted into the selected mass size, which mass can be manufactured either as a casting or from machined bar stock with a center opening of the mass being machined to tight tolerances so that the bushing can be pressed in and held by a press fit engagement without requiring additional attachment fasteners.
Another objective of the invention is to provide such a vibration damper in which the damper is attached easily to the vehicle by use of a single bolt or other fastener which extends through the bore of the inner metal sleeve to suspend the damper from the structural member, such as the interior of a vehicle seat.
These objectives and advantages are obtained by the vibration damper of the present invention, the general nature of which includes inner and outer coaxial sleeves defining an annular space therebetween; an elastomeric member disposed in at least a portion of the annular space and secured to the inner and outer sleeves and interconnecting said sleeves; a mass secured to the outer sleeve for movement with said sleeve; attachment means for mounting the inner sleeve to the structure whereby said outer sleeve and mass is free to oscillate about said inner sleeve to dampen out vibration on the structure; and an anti-rotation device for limiting angular movement of the mass about the inner sleeve.
These objectives and advantages are further obtained by the method of the present invention, the general nature of which may be stated as including the steps of providing a mass having an opening formed therein; providing inner and outer coaxial sleeves; securing an elastomeric member to said inner and outer sleeves in an annular space formed between said sleeves to form a bushing assembly; and securing the bushing assembly to the mass within the opening in said mass.
REFERENCES:
patent: 2939326 (1960-06-01), Dietrich
patent: 3419111 (1968-12-01), Jones et al.
patent: 3813776 (1974-06-01), Frederickson et al.
patent: 4580666 (1986-04-01), Ferguson
patent: 4800306 (1989-01-01), Oberto
patent: 4889328 (1989-12-01), Uno et al.
patent: 5080331 (1992-01-01), De Fontenay
patent: 5190269 (1993-03-01), Ikeda et al.
patent: 5295653 (1994-03-01), Miyazaki et al.
patent: 5295670 (1994-03-01), Tsukamoto et al.
patent: 5769380 (1998-06-01), Hibi et al.
patent: 5799930 (1998-09-01), Willett
patent: 5876023 (1999-03-01), Hain et al.
patent: 5876024 (1999-03-01), Hain
LaFleur James W.
Lefferts Scott R.
Bridgestone/Firestone Inc.
Kingsbury Thomas R.
Oberleitner Robert J.
Sand Michael
Sy Mariano
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