192 clutches and power-stop control – Transmission and brake – Motor vehicle
Reexamination Certificate
2000-09-20
2001-10-30
Oberleitner, Robert J (Department: 3613)
192 clutches and power-stop control
Transmission and brake
Motor vehicle
C188S267100
Reexamination Certificate
active
06308813
ABSTRACT:
BACKGROUND
The present invention relates to controllable fluids used to control interlock mechanisms and more particularly to such mechanisms wherein the controllable fluid comprises a magnetorheological fluid.
A great variety of mechanical systems are controlled by cables, push rods, or other elongated force-transmitting members. Control systems of this type are widely employed, especially in vehicular and industrial applications. Such applications include machine tools, manufacturing equipment, and materials handling systems. For reasons of safety and/or process control, it is often desirable to lock out or otherwise immobilize such control systems and thereby prevent the operation of the controlled mechanical system.
An exemplary application is the brake transmission safety interlock (BTSI) system utilized in automobiles. A BTSI system operates to prevent a vehicle's transmission from being taken out of the “park” position if the braking system is not activated. In a typical BTSI system, the shift linkage has a cable-activated locking latch. This latch must be released, typically by activating a button associated with the shifter and communicating with the latch by a cable or push rod, before the transmission may be shifted out of the “park” position. BTSI systems further include some type of immobilizing device associated with the cable and communicating with the brake system. If the brake system is not activated, then the immobilizing device prevents movement of the cable and release of the latch.
A solenoid may be used to control the mechanical linkage, as in U.S. Pat. No. 4,887,702, which describes a typical latch mechanism as well as a particular solenoid controlled BTSI system. In this system, the latch release cable is associated with the plunger of a solenoid and activation of the solenoid draws the plunger and cable into the solenoid coil, thereby preventing further motion of the cable. In its inactive state, the plunger and cable are free to move back and forth. The solenoid and other components each present a potential failure point in the system. In addition, a system with several components bears a higher production cost.
Accordingly, there is a need in the art for improved interlock mechanisms and, more particularly, for interlock mechanisms that require fewer moving parts.
SUMMARY
The present invention relates to a magnetorheological fluid controlled interlock mechanism. The interlock mechanism preferably includes a hydraulic link that may be placed in a mechanical linkage or mechanism to prevent actuation unless properly activated with an electrical current. In one aspect, the present invention provides an interlock mechanism for an automotive transmission shift lever system which prevents the shift lever system from being disengaged from the PARK position unless the ignition is ON and the brake pedal is depressed.
Another aspect of the present invention enables a pre-load release function whereby the shifter button may be depressed before the brake pedal is pushed. The interlock mechanism will release once the interlock conditions are met without the user having to release and re-actuate the shifter button. Accordingly, the interlock system can store the shift button energy until all of the interlock conditions are met.
Another aspect of the present invention includes a check valve which prevents the interlock from becoming locked in the open position. The check valve allows the mechanism to re-engage regardless of the state of the interlock logic.
In accordance with the present invention there is an interlock mechanism comprising a first piston at least partially disposed within a first end of a tubular body and a second piston at least partially disposed within a second end of the tubular body, wherein the first piston and the second piston define a chamber within the tubular body. A valve is disposed within the tubular body dividing the chamber into a first chamber portion and a second chamber portion. The valve prevents a controllable fluid from flowing from the first chamber portion to the second chamber portion. A bypass channel provides a path for the controllable fluid to flow between the first chamber portion and the second chamber portion.
In accordance with another embodiment of the present invention there is an interlock system comprising a plunger at least partially disposed within one end of a tubular body. A first piston is axially oriented within the tubular body and means for translating an axial force are located between the plunger and the first piston. A second piston is also axially oriented within the tubular body. A valve is disposed within the tubular body and defines a first chamber between the first piston and a first end of the valve and a second chamber between the second end of the valve and the second piston. The valve prevents a controllable fluid from flowing from the first chamber to the second chamber. A bypass channel provides a path for the controllable fluid to flow between the first chamber and the second chamber, thereby bypassing the valve. In addition, a fluid control means is in proximity to the bypass channel.
In accordance with another embodiment of the present invention there is an interlock system comprising a plunger at least partially disposed within one end of a tubular body and a first piston axially oriented within the tubular body. The first piston is at least partially covered with a porous material coated with a controllable fluid. A compression spring is axially oriented within the tubular body with a first end of the compression spring engaging an end of the plunger. A second end of the compression spring engages a first end of the first piston. A fluid control means is disposed within the first piston.
In accordance with another aspect of the present invention there is an apparatus for selectively translating axial motion comprising a housing defining a channel having at least a first end and a second end. A first piston assembly is at least partially disposed within the first end of the channel and slidably movable along a first axis. A second piston assembly is at least partially disposed within the second end of the channel and slidably movable along a second axis. A valve assembly is disposed within the channel and defines a first reservoir and a second reservoir. A first fluid communication path flow connects the first reservoir and the second reservoir. In addition, a second fluid communication path flow connects the first reservoir and the second reservoir. A controllable fluid is disposed within at least the first reservoir. In addition, there is an assembly for selectively applying a field to the second communication path to change the viscosity of the controllable fluid in the second fluid communication path.
In accordance with another aspect of the present invention, there is a method of manufacturing an assembly for selectively translating axial motion. The assembly comprises a housing having a channel extending therethrough. The channel has a valve assembly disposed within the channel dividing the channel into a first chamber portion and a second chamber portion. At least a first fluid path connects the first chamber portion to the second chamber portion. A method of manufacturing the assembly comprises the steps of
disposing a first piston assembly at least partially within the first chamber portion; disposing a second piston assembly at least partially within the second chamber portion; and disposing a controllable fluid within at least the first chamber portion.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
REFERENCES:
patent: 2820471 (1958-01-01), Crowell
patent: 2940749 (1960-06-01), Kemelhor
patent: 4097833 (1978-06-01), Myers
patent: 4241814 (1980-12-01), Masclet
patent: 4729459 (1988-03-01), Inagaki et al.
patent: 4887702 (1989-12-01), Ratke
patent: 4986689 (1991-01-01), Drutchas
patent: 5058462 (1991-10-01), Killiany et al.
patent: 5078242
Gnibus Michael M.
Lord Corporation
Oberleitner Robert J
Pezzlo Benjamin A.
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