Brakes – Internal-resistance motion retarder – With fluid regulated in response to inertia of valve member
Reexamination Certificate
2000-05-17
2001-04-24
Butler, Douglas C. (Department: 3613)
Brakes
Internal-resistance motion retarder
With fluid regulated in response to inertia of valve member
C188S322130, C267S221000, C267S226000
Reexamination Certificate
active
06220406
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to shock absorbers which create an anti-roll system for a vehicle. More particularly, the present invention relates to shock absorbers having a passive damping system for providing variable damping in response to lateral forces placed upon the vehicle.
2. Description of the Related Art
Various types of shock absorbers are used in connection with motor vehicle suspension systems to absorb unwanted vibrations which occur during various driving conditions. To dampen the unwanted vibrations, shock absorbers are generally connected between the sprung portion (i.e., the vehicle body) and the unsprung (i.e., the suspension) of the vehicle. A piston assembly is located within the working chamber of the shock absorber and is connected to the body of the motor vehicle through a piston rod. Generally, the piston assembly includes a primary valving arrangement that is able to limit the flow of damping fluid within the working chamber when the shock absorber is compressed or extended. As such, the shock absorber is able to generate a damping force which “smooths” or “dampens” the vibrations transmitted from the suspension to the vehicle body. Typically, these vibrations occur from forces generated in a vertical direction between the vehicle body and the driving surface.
The greater the degree to which the flow of damping fluid within the working chamber is restricted across the piston assembly, the greater the damping forces which are generated by the shock absorber. It is also possible to implement a primary valving arrangement which produces one magnitude of damping on the compression stroke, and a second magnitude of damping on the rebound stroke. However, these different damping rates are typically constant because they are produced by varying the sizes of the compression and rebound bypass orifices.
While these shock absorbers produce ride comfort levels ranging from “soft” to “firm,” few, if any, of the known shock absorbers produce varying degrees of damping in a passive manner. The shock absorber systems known within the art which are capable of producing varying degrees of damping force, typically achieve this through the use of active control systems. However, these systems generally react to the vertically generated forces placed upon the vehicle suspension.
Accordingly, it is desirable to provide a shock absorber which includes a primary damping mechanism for counteracting the vertical forces placed upon the vehicle, and a secondary damping mechanism which is capable of providing varying damping in response to horizontal and lateral forces which are placed upon the vehicle suspension. Further, it is desirable that this secondary and variable damping be provided in proportion to the lateral force encountered by a passive control or valving arrangement. Such a system could be used to implement a passive anti-roll system for enhancing the control to the vehicle provided by the vehicle suspension. Such a passive damping system also eliminates the need for complicated and expensive control systems which actively provide the varying degrees of damping.
An example of the lateral forces placed upon the vehicle suspension are the lateral forces generated during high-speed cornering. As these lateral forces are counteracted by the vehicle's suspension and tires, a rolling action on the vehicle body is produced. When these rolling forces exceed the limit for the vehicle, a rollover condition may be created where the vehicle is literally flipped over on its side. Accordingly, it is desirable to provide a shock absorber which provides increased damping in response to these lateral and horizontal forces for counteracting or at least minimizing these rolling forces.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide a passive damping system for a shock absorber which can be used to implement a passive anti-roll system for a vehicle. The shock absorber includes a working chamber, and a piston disposed in the working chamber. The piston includes a primary bypass valve for defining an upper fluid portion and a lower fluid portion. A piston rod is connected to the piston and extends through the top portion of the working chamber. A variable bypass assembly is disposed between a first fluid chamber and a second fluid chamber, and includes at least one bypass aperture for providing communication of damping fluid between the first and second fluid chambers. The variable bypass assembly also includes a passive control member for varying the size of the bypass aperture, and biasing means for normally retaining the passive control member in a position which maximizes the size of the bypass aperture. The passive control member is such that an accelerating force placed upon the shock absorber causes motion of the passive control member for restricting the size of the bypass aperture and increasing a damping force provided by the shock absorber.
Various other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings and the appended claims.
REFERENCES:
patent: 1281079 (1918-10-01), Sears
patent: 1857750 (1932-05-01), Wilbur
patent: 2606630 (1952-08-01), Rossman
patent: 2774448 (1956-12-01), Hultin
patent: 2877872 (1959-03-01), Krizan
patent: 2957703 (1960-10-01), Ross
patent: 3414092 (1968-12-01), Speckhart
patent: 3706362 (1972-12-01), Faure
patent: 3862751 (1975-01-01), Schwaller
patent: 3895816 (1975-07-01), Takahashi et al.
patent: 3945626 (1976-03-01), Tilkens
patent: 3966030 (1976-06-01), Sirven
patent: 4004662 (1977-01-01), Sorgatz et al.
patent: 4126302 (1978-11-01), Curnutt
patent: 4148469 (1979-04-01), Geyer
patent: 4153237 (1979-05-01), Supalla
patent: 4162062 (1979-07-01), Strauss
patent: 4210344 (1980-07-01), Curnutt
patent: 4226408 (1980-10-01), Tomita et al.
patent: 4254849 (1981-03-01), Pohlenz
patent: 4274515 (1981-06-01), Bourcier de Carbon
patent: 4328960 (1982-05-01), Handke et al.
patent: 4527674 (1985-07-01), Mourray
patent: 4546959 (1985-10-01), Tanno
patent: 4660686 (1987-04-01), Munning et al.
patent: 4673067 (1987-06-01), Munning et al.
patent: 4762308 (1988-08-01), Geno
patent: 4768629 (1988-09-01), Wossner
patent: 4786034 (1988-11-01), Heess et al.
patent: 4834088 (1989-05-01), Jeanson
patent: 4838393 (1989-06-01), Mourray et al.
patent: 4907680 (1990-03-01), Wolfe et al.
patent: 4917222 (1990-04-01), Bacardit
patent: 4997068 (1991-03-01), Ashiba
patent: 5024301 (1991-06-01), Cook
patent: 5043649 (1991-08-01), Murakami et al.
patent: 5080205 (1992-01-01), Miller et al.
patent: 5095581 (1992-03-01), Sarto
patent: 5146948 (1992-09-01), Runkel
patent: 5154442 (1992-10-01), Milliken
patent: 5201388 (1993-04-01), Malm
patent: 5201389 (1993-04-01), Miller et al.
patent: 5213183 (1993-05-01), Maurer
patent: 5269557 (1993-12-01), Butsuen et al.
patent: 5269558 (1993-12-01), Yoshioka et al.
patent: 5307907 (1994-05-01), Nakamura et al.
patent: 5332068 (1994-07-01), Richardson et al.
patent: 5360230 (1994-11-01), Yamada et al.
patent: 5437354 (1995-08-01), Smith
patent: 5462140 (1995-10-01), Cazort et al.
patent: 5598903 (1997-02-01), Richardson
patent: 5823305 (1998-10-01), Richardson et al.
patent: 6102170 (2000-08-01), de Molina et al.
patent: 1 209 007 (1966-01-01), None
patent: 0 744 307 A1 (1996-11-01), None
patent: 2 252 508 (1973-11-01), None
patent: 54-44167 (1979-04-01), None
patent: 4-296234 (1992-10-01), None
de Molina Simon Anne
Deferme Stefan
Butler Douglas C.
Harness Dickey & Pierce PLC
Tenneco Automotive Inc.
LandOfFree
Passive anti-roll system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Passive anti-roll system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Passive anti-roll system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2513881