Patent US5054650A successfully refreshed from Google Patents.
US5054650A
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Method of compensating for changes in the flow characteristics of a dispensed fluid to maintain the volume of dispensed fluid at a setpoint
Assignee: Nordson Corp
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Filing: 1990-03-08
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Granted: 1991-10-08
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Expires: 2010-03-08
Abstract
Abstract Changes in the flow characteristics of a fluid being dispensed from a nozzle under then control of a metering valve are compensated for in order to maintain the volume of fluid dispensed over a predetermined time interval substantially equal to a selected setpoint. The volume of fluid delivered to the metering valve during a predetermined interval is measured and a correction factor based on the difference between the measured volume and the setpoint is calculated. The correction factor is used to generate a driving signal from which a control signal applied to the metering valve is generated.
Inventors
- 👤 Richard P. Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:48
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635; B; B05; B05B; B05B12/00; B05B12/08; B05B12/085; B05B13/00; B05B13/02; B05B13/04; B05B13/0431; B05C; B05C5/00; B05C5/02; B05C5/0225; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0324; Y10T137/7722; Y10T137/7758; Y10T137/7761
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
118 words
A method of compensating for changes in the flow characteristics of a fluid being dispensed from a nozzle under the control of a metering valve in order to maintain the volume of fluid dispensed over a predetermined time interval at a desired setpoint, said method comprising the steps of: (a) measuring the volume of fluid delivered to the metering valve during at least one said interval; (b) calculating a correction factor correlated to the difference between said measured volume and said setpoint, (c) multiplying a signal by said factor to generate a driving signal, and (d) controlling said valve in accordance with at least said driving signal to maintain the volume of fluid dispensed at said desired setpoint.
Claim 2
Independent Claim
118 words
A method of compensating for changes in the flow characteristics of a fluid being dispensed from a nozzle under the control of a metering valve in order to maintain the volume of fluid dispensed over a predetermined time interval at a desired setpoint, said method comprising the steps of: (a) measuring the volume of fluid delivered to the metering valve during at least one said interval; (b) calculating a correction factor correlated to the difference between said measured volume and said setpoint, (c) multiplying a signal by said factor to generate a driving signal, and (d) controlling said valve in accordance with at least said driving signal to maintain the volume of fluid dispensed at said desired setpoint.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein said controlling step includes the step of applying a signal correlated to said driving signal to a closed-loop feedback system coupled to said metering valve.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein said correction factor comprises a quotient whose dividend is said setpoint and whose divisor is said measured volume of fluid.
Claim 5
Independent Claim
124 words
A method for compensating for changes in the flow characteristics of a fluid being dispensed from a nozzle, said method comprising the steps of: (a) delivering the fluid under pressure to a metering valve located upstream of the nozzle, said metering valve being operable to modulate the flow of fluid to the nozzle in response to a control signal; (b) measuring the volume of fluid delivered to said metering valve over an interval of time and generating a corresponding measurement signal, and (c) adjusting the control signal in accordance with the difference between said measurement signal and a setpoint representing a desired volume of fluid to be dispensed during said interval so that said valve maintains the volume of fluid dispensed at said setpoint.
Claim 6
Independent Claim
124 words
A method for compensating for changes in the flow characteristics of a fluid being dispensed from a nozzle, said method comprising the steps of: (a) delivering the fluid under pressure to a metering valve located upstream of the nozzle, said metering valve being operable to modulate the flow of fluid to the nozzle in response to a control signal; (b) measuring the volume of fluid delivered to said metering valve over an interval of time and generating a corresponding measurement signal, and (c) adjusting the control signal in accordance with the difference between said measurement signal and a setpoint representing a desired volume of fluid to be dispensed during said interval so that said valve maintains the volume of fluid dispensed at said setpoint.
Claim 7
Dependent Claim
47 words
The method of claim 4 wherein said adjusting step comprises the steps of: calculating a correction factor correlated to the difference between said measurement signal and said setpoint; multiplying a driving signal by said correction factor, and generating said control signal from at least said driving signal.
Claim 8
Dependent Claim
36 words
The method of claim 5 wherein said generating step comprises the step of algebraically combining the difference between said driving signal with a signal correlated to the flow rate of the fluid dispensed from the nozzle.
Claim 9
Dependent Claim
35 words
The method of claim 6 further comprising the step of: generating said driving signal in accordance with at least a toolspeed signal of a robot for effecting relative movement between the nozzle and a workpiece.
Claim 10
Dependent Claim
30 words
The step of claim 7 wherein said signal correlated to the flow rate of the fluid dispensed from the nozzle comprises a signal representing the pressure drop across said nozzle.
Claim 11
Dependent Claim
12 words
The method of claim 4 wherein said interval is a job cycle.
Claim 12
Dependent Claim
84 words
The method of claim 4 further comprising the steps of: locating said valve and said nozzle in sufficiently close proximity to one another that very little fluid pressure drop occurs between said valve and said nozzle; sensing, at a location between said valve and said nozzle, a parameter correlated to the rate of flow of the fluid discharged from the nozzle and generating a corresponding flow rate signal, and generating said control signal from at least said flow rate signal and a driving signal.
Claim 13
Dependent Claim
44 words
The method of claim 10 further comprising the steps of: calculating a correction factor correlated to the difference between said measurement signal and said setpoint; multiplying a driving signal by said correction factor, and generating said control signal from at least said driving signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-10-07 | 1995-04-08 | 1995-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-07 | 1999-04-08 | 1999-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-07 | 2003-04-08 | 2003-10-08 | $7700.00 | Window Closed / Lapsed |