US4922852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for dispensing fluid materials
Assignee: Nordson Corp
•
Filing: 1988-09-07
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Granted: 1990-05-08
•
Expires: 2008-09-07
Abstract
Abstract Apparatus and method for dispensing fluid material whereby the fluid is discharged from a nozzle onto a workpiece. Delivery of fluid to the nozzle is controlled by a metering valve located in close proximity to the nozzle. The flow of dispensed fluid is sensed by a pressure transducer disposed to sense the pressure drop across the nozzle. The pressure transducer generates a feedback signal which can be applied by way of a closed loop control system to an electropneumatic servovalve which operates a double-acting air cylinder the pressure drop across the nozzle thereby controlling the flow of dispensed fluid in accordance with a driving signal. Where the dispenser is carried by a robot, the driving signal can be correlated to the relative speed between the workpiece and the nozzle to accurately control the amount of fluid per unit length contained in a bead deposited on the surface of the workpiece. Due to the rapid response of the system such precise control is possible even during relatively rapid changes in the relative speed between the nozzle and the workpiece. Also disclosed are means for insuring that the volume of fluid dispensed over a predetermined interval corresponds to a desired setpoint thereby correcting for changes in the intrinsic viscosity of the dispensed fluid as may be caused by changes in its temperature.
Inventors
- 👤 Richard P. Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:04
CPC Classifications
B; B05; B05C; B05C5/00; B05C5/02; B05C5/0225; B05B; B05B12/00; B05B12/08; B05B12/085; B05B13/00; B05B13/02; B05B13/04; B05B13/0431; G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635; B05C5/0208; B05C5/0212; B05C5/0216
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
283 words
An apparatus for dispensing fluid material onto a workpiece, said apparatus comprising: (a) a fluid inlet connectable to a pressurized supply of fluid; (b) a valve having a valve inlet and a valve outlet, said valve communication with said fluid inlet and being operable to substantially infinitely variably modulate flow of the fluid when said valve is at least partially open and to positively cut off flow when said valve is closed; (c) a dispensing nozzle disposed downstream of said valve, said nozzle having a nozzle inlet and a nozzle outlet, said nozzle inlet being positioned in sufficiently close proximity to said valve outlet that very little fluid pressure drop occurs in a region of flow including said valve outlet and said nozzle inlet in relation to the pressure drop across said nozzle when said valve is at least partially open; (d) a sensor operably communicating with said region in close proximity to both said valve outlet and said nozzle inlet for sensing a parameter other than the position of a flow restricting element, said parameter being correlated to the rate of flow of the fluid discharged from said nozzle outlet and generating a corresponding flow rate signal, and (e) an actuator connected to said valve, said actuator being responsive to said flow rate signal to control the rate of flow of fluid discharged from said nozzle outlet when said valve is at least partially open; whereby the flow of fluid is modulated by said valve and sensed in close proximity to said nozzle inlet within said region of flow, the instantaneous fluid pressure within which substantially equals the fluid pressure at said nozzle inlet to provide said apparatus with enhanced response characteristics.
Claim 2
Independent Claim
283 words
An apparatus for dispensing fluid material onto a workpiece, said apparatus comprising: (a) a fluid inlet connectable to a pressurized supply of fluid; (b) a valve having a valve inlet and a valve outlet, said valve communication with said fluid inlet and being operable to substantially infinitely variably modulate flow of the fluid when said valve is at least partially open and to positively cut off flow when said valve is closed; (c) a dispensing nozzle disposed downstream of said valve, said nozzle having a nozzle inlet and a nozzle outlet, said nozzle inlet being positioned in sufficiently close proximity to said valve outlet that very little fluid pressure drop occurs in a region of flow including said valve outlet and said nozzle inlet in relation to the pressure drop across said nozzle when said valve is at least partially open; (d) a sensor operably communicating with said region in close proximity to both said valve outlet and said nozzle inlet for sensing a parameter other than the position of a flow restricting element, said parameter being correlated to the rate of flow of the fluid discharged from said nozzle outlet and generating a corresponding flow rate signal, and (e) an actuator connected to said valve, said actuator being responsive to said flow rate signal to control the rate of flow of fluid discharged from said nozzle outlet when said valve is at least partially open; whereby the flow of fluid is modulated by said valve and sensed in close proximity to said nozzle inlet within said region of flow, the instantaneous fluid pressure within which substantially equals the fluid pressure at said nozzle inlet to provide said apparatus with enhanced response characteristics.
Claim 3
Dependent Claim
12 words
The apparatus of claim 1 wherein said sensor comprises a pressure sensor.
Claim 4
Dependent Claim
20 words
The apparatus of claim 2 wherein said pressure sensor is operably disposed to sense the differential pressure across said nozzle.
Claim 5
Dependent Claim
17 words
The apparatus of claim 1 wherein said actuator comprises a double-acting cylinder driven by an electro-pneumatic servovalve.
Claim 6
Dependent Claim
29 words
The apparatus of claim 4 wherein said servovalve is a type selected from the group consisting of, a jet-pipe servovalve, a spool servovalve, and a nozzle and flapper servovalve.
Claim 7
Dependent Claim
63 words
The apparatus of claim 1 further comprising means for moving said nozzle relative the workpiece and generating a toolspeed signal correlated to the speed of said relative movement, said actuator being responsive to said toolspeed signal as well as to said flow rate signal in order to control the amount of fluid dispensed onto the workpiece per unit distance of said relative movement.
Claim 8
Dependent Claim
12 words
The apparatus of claim 6 wherein said sensor comprises a pressure sensor.
Claim 9
Dependent Claim
20 words
The apparatus of claim 7 wherein said pressure sensor is operably disposed to sense the differential pressure across said nozzle.
Claim 10
Dependent Claim
17 words
The apparatus of claim 6 wherein said actuator comprises a double-acting cylinder driven by an electro-pneumatic servovalve.
Claim 11
Dependent Claim
29 words
The apparatus of claim 9 wherein said servovalve is a type selected from the group consisting of, a jet-pipe servovalve, a spool servovalve and a nozzle and flapper servovalve.
Claim 12
Dependent Claim
80 words
The apparatus of claim 1 further comprising: (a) a flowmeter operably connected to said valve to generate a volume signal correlated to the volume of fluid delivered to said valve within a predetermined interval; and (b) a controller operable to compare said volume signal with a predetermined setpoint and to adjust excitation of said actuator to compensate for any difference between said volume signal and said setpoint in order to account for changes in the flow characteristics of the fluid.
Claim 13
Dependent Claim
14 words
The apparatus of claim 11 wherein said interval comprises at least one job cycle.
Claim 14
Dependent Claim
13 words
The apparatus of claim 11 wherein said flowmeter comprises a positive displacement flowmeter.
Claim 15
Independent Claim
114 words
An apparatus for dispensing fluid material comprising: (a) a nozzle for discharging the fluid; (b) metering valve means located upstream of said nozzle and in close proximity thereto for controlling delivery of the fluid to said nozzle; (c) sensing means operably disposed between said nozzle and said valve means for sensing a parameter correlated to the rate of flow of the fluid discharged from said nozzle and generating a corresponding flow rate signal; and (d) an actuator connected to said valve, said actuator comprising a double-acting cylinder driven by an electro-pneumatic servovalve, said actuator being responsive to said flow rate signal to control the rate of flow of the fluid discharged from said nozzle.
Claim 16
Independent Claim
114 words
An apparatus for dispensing fluid material comprising: (a) a nozzle for discharging the fluid; (b) metering valve means located upstream of said nozzle and in close proximity thereto for controlling delivery of the fluid to said nozzle; (c) sensing means operably disposed between said nozzle and said valve means for sensing a parameter correlated to the rate of flow of the fluid discharged from said nozzle and generating a corresponding flow rate signal; and (d) an actuator connected to said valve, said actuator comprising a double-acting cylinder driven by an electro-pneumatic servovalve, said actuator being responsive to said flow rate signal to control the rate of flow of the fluid discharged from said nozzle.
Claim 17
Dependent Claim
29 words
The apparatus of claim 14 wherein said servovalve is a type selected from the group consisting of, a jet-pipe servovalve, a spool servovalve, and a nozzle and flapper servovalve.
Claim 18
Independent Claim
140 words
An apparatus for dispensing fluid material onto a workpiece, said apparatus comprising: (a) a nozzle movable relative to the workpiece for discharing the fluid; (b) valve means located upstream of said nozzle and in close proximity thereto for controlling delivery of the fluid to said nozzle; (c) sensing means operably disposed between said nozzle and said valve means for sensing a parameter correlated to the rate of flow of the fluid discharged from said nozzle and generating a corresponding flow rate signal; and (d) an actuator connected to said valve means, said actuator comprising a double-acting cylinder driven by an electro-pneumatic servovalve, said actuator being responsive to said flow rate signal and to a toolspeed signal correlated to the speed of said relative movement between said workpiece and said nozzle to control the amount of fluid dispensed onto the workpiece.
Claim 19
Independent Claim
140 words
An apparatus for dispensing fluid material onto a workpiece, said apparatus comprising: (a) a nozzle movable relative to the workpiece for discharing the fluid; (b) valve means located upstream of said nozzle and in close proximity thereto for controlling delivery of the fluid to said nozzle; (c) sensing means operably disposed between said nozzle and said valve means for sensing a parameter correlated to the rate of flow of the fluid discharged from said nozzle and generating a corresponding flow rate signal; and (d) an actuator connected to said valve means, said actuator comprising a double-acting cylinder driven by an electro-pneumatic servovalve, said actuator being responsive to said flow rate signal and to a toolspeed signal correlated to the speed of said relative movement between said workpiece and said nozzle to control the amount of fluid dispensed onto the workpiece.
Claim 20
Dependent Claim
29 words
The apparatus of claim 16 wherein said servovalve is a type selected from the group consisting of, a jet-pipe servovalve, a spool servovalve and a nozzle and flapper servovalve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |