US5054650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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
•
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 17:07
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.
References Cited (Backward Citations)
US2851997A
Cited
US3015768A
Cited
US3434690A
Cited
US3464627A
Cited
US3410301A
Cited
US3555970A
Cited
GB1325091A
Cited
US3643699A
Cited
US3666141A
Cited
US3779426A
Cited
US3724720A
Cited
US3757823A
Cited
US3827603A
Cited
DE2327263A1
Cited
US3901266A
Cited
US3924840A
Cited
US3961608A
Cited
US3817150A
Cited
US3945399A
Cited
US4013037A
Cited
US4066188A
Cited
US4084539A
Cited
US4133511A
Cited
US4232517A
Cited
US4164001A
Cited
US4301944A
Cited
US4246969A
Cited
US4478775A
Cited
GB2049228A
Cited
DE2924264A1
Cited
US4464976A
Cited
EP0029236A1
Cited
DE3109303A1
Cited
GB2074240A
Cited
US4465212A
Cited
US4360132A
Cited
GB2080574A
Cited
US4392366A
Cited
US4472967A
Cited
DD203236A1
Cited
US4430886A
Cited
US4614300A
Cited
EP0098719A2
Cited
EP0104546A2
Cited
DE8227606U1
Cited
US4667852A
Cited
US4662540A
Cited
EP0163069A1
Cited
WO1986003855A1
Cited
US4724864A
Cited
US4711379A
Cited
US4613059A
Cited
US4678100A
Cited
US4700205A
Cited
US4878598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 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 |