Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
2002-01-18
2004-06-15
Patel, Ramesh (Department: 2121)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C700S250000, C239S373000, C118S323000
Reexamination Certificate
active
06751520
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to intrinsically safe pressure regulators and, more particularly, to an intrinsically safe control system for a pressure regulator for operation in a hazardous environment.
BACKGROUND OF THE INVENTION
Many industrial environments utilize chemicals, solvents, and other compositions which are often volatile and create hazardous atmospheres. Some industries operate electronic equipment in these hazardous atmospheres. Because the hazardous atmospheres are often flammable, electronic equipment operating in these atmospheres preferably is designed to reduce the opportunity for igniting the hazardous atmosphere. This is accomplished by limiting the energy required to operate the electronic equipment, thereby significantly reducing the opportunity for creating sparks and other igniting phenomenon, such as heat.
In a particular example, manufacturers of automobiles utilize paint booths in which robots paint the vehicles. The robots efficiently apply paint to the vehicles. When the robots spray paint, a paint spray atmosphere is created. The paint spray atmosphere is typically a flammable or hazardous environment due to the composition of chemicals used in the paint process. Certain areas of the paint booth are considered hazardous and require utilization of intrinsically safe equipment, while other areas of the paint booth are non-hazardous and do not require utilization of intrinsically safe equipment. With respect to a paint robot, air pressure causes the discharge of paint from a paint gun typically located at the end of a robot arm. The air pressure generated to control the paint functions typically is modulated through use of pilot pressures that modulate the output pressure that controls various paint gun functions. Operating solenoids typically creates the pilot pressure.
In a typical paint operation, is desirable to accurately and quickly vary the flow rate of paint to adjust to the contours of the vehicle in order to optimally apply the paint. Accurately and quickly controlling the application of paint typically requires utilizing a controller in a closed loop mode. The controller compares a downstream pressure against a target pressure and creates an error signal to adjust the paint flow.
In such systems, designers favor placing pressure control valves to control the flow of paint as close to the paint gun as possible. Several factors limit how close the pressure control valves can be placed to the paint gun. First, the pressure control valves are typically operated electronically. In order to operate the pressure control valves as close to the paint gun as possible, the pressure control valves must be intrinsically safe. Otherwise, the pressure control valves must be located outside of the hazardous area. When located outside the hazardous area, the pressure control valves are typically further from the tip of the paint gun. This results in a slower response time at the paint gun, thereby reducing the ability to optimally control the paint flow. Further, existing technologies do not provide pressure control valves which operates in an intrinsically safe mode when considered in conjunction with the control devices which operate the pressure control valves. Thus, the control package, including a controller and a pressure control valve, typically operates outside the hazardous area, so as to meet intrinsically safe standards.
SUMMARY OF THE INVENTION
The present invention is directed to an intrinsically safe pressure control system for controlling operation of a device, where a portion of the system operates in a safe area, and a portion of system operates in a hazardous area. The control system includes a controller located within the hazardous area. The controller receives input signals from the safe area and generates a control signal. A first piezo electrically controlled valve is located within the hazardous area. The piezo electrically controlled valve generates a pressure in response to the control signal.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
REFERENCES:
patent: 4024961 (1977-05-01), Stolpe
patent: 4300198 (1981-11-01), Davini
patent: 4532148 (1985-07-01), Vecellio
patent: 4561592 (1985-12-01), Fender et al.
patent: 4611695 (1986-09-01), Kato et al.
patent: 4614164 (1986-09-01), Kato et al.
patent: 4812294 (1989-03-01), Combs
patent: 4827395 (1989-05-01), Anders et al.
patent: 4838311 (1989-06-01), Vetter
patent: 4914721 (1990-04-01), Glaeser et al.
patent: 4951873 (1990-08-01), Ashworth et al.
patent: 4957060 (1990-09-01), Cann
patent: 5079491 (1992-01-01), Nose et al.
patent: 5127363 (1992-07-01), Nakamura et al.
patent: 5429682 (1995-07-01), Harlow, Jr. et al.
patent: 5636798 (1997-06-01), Buschor
patent: 5730359 (1998-03-01), Wurth
patent: 5949683 (1999-09-01), Akami et al.
patent: 5964407 (1999-10-01), Sandkleiva
patent: 5980994 (1999-11-01), Honma et al.
patent: 5989643 (1999-11-01), Nakagawa et al.
patent: 6082290 (2000-07-01), Conlin
patent: 6190454 (2001-02-01), Anderson
patent: 6257700 (2001-07-01), Aihara et al.
patent: 6276057 (2001-08-01), Aihara et al.
patent: 6346150 (2002-02-01), Conlin
patent: 6398870 (2002-06-01), Kaya et al.
patent: 6439480 (2002-08-01), Velde
patent: 6443371 (2002-09-01), Arnfindsen
patent: 6477913 (2002-11-01), Akeel et al.
patent: 6497476 (2002-12-01), Namba et al.
patent: 2003/0136336 (2003-07-01), Fouvet et al.
patent: 196 44 801 (1998-05-01), None
patent: 0 794 370 (1997-09-01), None
patent: 11076887 (1999-03-01), None
Beetz, M. “Structured Reactive Controllers-Controlling Robots that Perform Everyday activity”, Proceedings of the 3rd Annual Conference on Autonomous Agents, 1999, pp. 228-235.*
Santa et al., “Development of a Neural Controller for Motion Control of a Piezoelectric Three-Legged Micromanipulation Robot” Proceedings of the 1998 IEEE/RSJ Intl. Conf on Intelligent Robots and Systems, Oct. 1998, pp. 788-793.
Mathewes Christopher W.
Schrobenhauser Max
Vollmer Josef
Worde Lawrence J.
Booker Kelvin
Lollo Frank L.
MacMillan Sobanski & Todd
Mollon Mark L.
Patel Ramesh
LandOfFree
Intrinsically safe microprocessor controlled pressure regulator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intrinsically safe microprocessor controlled pressure regulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intrinsically safe microprocessor controlled pressure regulator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3365648