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US 5,329,966 AGranted
Gas flow controller
AssigneeVICI Metronics, Inc.
InventorsDavid C. Fenimore, Walter H. McHenry, James L. Blumberg
Life of this patent
Estimating the term…
Abstract
There is disclosed a system for delivering gas at a predetermined rate of flow, including a diaphgram type flow controller, a pressure regulator for providing a constant flow of gas to the flow controller, and a microprocessor controlled stepper motor utilizing an optical encoder to adjust the rate of flow of a gas leaving the controller without having to use a gas flow measurement device to monitor the flow rate.
Claims12
In a system for delivering gas at a predetermined rate of flow, comprising:
- a flow controller having a diaphragm forming upstream and downstream chambers;
- means for delivering gas to the upstream chamber of the flow controller at a substantially constant pressure;
- said controller having an outlet from the downstream chamber which is opened and closed by the diaphragm;
- means connecting the upstream and downstream chambers and having a fixed orifice therein;
- spring means urging the diaphragm toward its closed position;
- and
- means for selectively adjusting the spring force to achieve the predetermined rate of flow without having to use a gas flow measurement device to monitor the flow rate.
4 more elements
For use in a system for delivering gas at a predetermined rate of flow:
- a diaphragm type gas flow controller and whose diaphragm is moved by a rotatable stem to a position corresponding to the predetermined rate of flow of the gas leaving the flow controller;
- a stepper motor for rotating the rotatable stem;
- means for determining a rotative position of the rotatable stem representative of a reference point;
- and
- processing means connected to said stepper motor for determining a number of steps which are required to rotate the stem to achieve the predetermined flow rate of the gas being controlled relative to the reference point and actuating said stepper motor to take the number of steps from the reference point.
2 more elements
Dependencies are inferred from the claim text.