US4621268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid application method and apparatus
Assignee: Willett International Ltd
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Filing: 1985-02-05
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Granted: 1986-11-04
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Expires: 2005-02-05
Abstract
Abstract Fluid is applied in droplet form to a substrate by feeding the fluid to a nozzle so that the fluid issues from the nozzle as a single substantially coherent jet following a single jet flight path, causing the jet to break up into a series of substantially uniformly sized droplets, and applying a sufficiently large electrical charge to the fluid by means of a charge electrode so as to form mutually repellant droplets having flight paths which diverge from one another. The single jet path is directed into a catching device by which the fluid is caught and prevented from being applied to the substrate. The jet of fluid is broken up into a stream of substantially uniformly spaced droplets and the divergent stream of droplets is directed away from the catching device and allowed to reach the substrate so as to deposit fluid on the substrate.
Inventors
- 👤 Michael R. Keeling
- 👤 David J. Langrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:11
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/02; B05D1/04; B05B; B05B5/00; B05B5/08; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/02; B41J2/03
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
154 words
A method for applying a fluid in droplet form to a substrate, said method comprising: feeding the fluid to a nozzle such that said fluid issues from said nozzle as a single substantially coherent jet following a single flight path directed toward a catching means by which the fluid is caught and prevented from being applied to the substrate; applying a sufficiently large electrical charge to said single jet of fluid by means of a charge electrode so as to form a plurality of mutually repellant charge fluid droplets having flight paths which diverge from one another to form a generally conical spray of charged fluid droplets; and causing relative movement between said catching means and said conical spray of charged droplets, thereby to prevent said charged droplets from being caught by said catching means and allowing said charged droplets to reach said substrate, when it is desired to deposit fluid on said substrate.
Claim 2
Independent Claim
154 words
A method for applying a fluid in droplet form to a substrate, said method comprising: feeding the fluid to a nozzle such that said fluid issues from said nozzle as a single substantially coherent jet following a single flight path directed toward a catching means by which the fluid is caught and prevented from being applied to the substrate; applying a sufficiently large electrical charge to said single jet of fluid by means of a charge electrode so as to form a plurality of mutually repellant charge fluid droplets having flight paths which diverge from one another to form a generally conical spray of charged fluid droplets; and causing relative movement between said catching means and said conical spray of charged droplets, thereby to prevent said charged droplets from being caught by said catching means and allowing said charged droplets to reach said substrate, when it is desired to deposit fluid on said substrate.
Claim 3
Dependent Claim
35 words
A method as claimed in claim 1, wherein said applying comprises operating said charge electrode at a voltage of at least 1000 volts with respect to said fluid issuing through an orifice of said nozzle.
Claim 4
Dependent Claim
45 words
A method as claimed in claim 1, wherein said causing comprises deflecting said conical spray of charged droplets from said catching means by applying an electrical field to said conical spray of droplets by means of a deflecting electrode located downstream of said charging electrode.
Claim 5
Dependent Claim
22 words
A method as claimed in claim 3, comprising operating said deflecting electrode at the same polarity and voltage as said charging electrode.
Claim 6
Dependent Claim
20 words
A method as claimed in claim 4, wherein said deflecting electrode is formed as an extension of said charging electrode.
Claim 7
Dependent Claim
23 words
A method as claimed in claim 1, comprising subjecting said single jet of fluid to pulses to induce controlled formation of the droplets.
Claim 8
Dependent Claim
32 words
A method as claimed in claim 6, comprising causing said single jet of fluid to break up into droplets by applying said pulses to said fluid by means of a piezoelectric crystal.
Claim 9
Dependent Claim
19 words
A method as claimed in claim 1, wherein said fluid has a conductivity of at least 250 micro Siemens.
Claim 10
Dependent Claim
29 words
A method as claimed in claim 1, wherein said fluid is selected from ink and adhesive compositions having a viscosity of from 2 to 200 cps at 25° C.
Claim 11
Dependent Claim
17 words
A method as claimed in claim 1, wherein said droplets have a diameter greater than 70 microns.
Claim 12
Independent Claim
160 words
An apparatus for applying a fluid in droplet form to a substrate, said apparatus comprising: a source of fluid under pressure; a nozzle in fluid communication with said fluid source for discharging said fluid as a single substantially coherent stream following a single flight path; means, located along said flight path, for catching said fluid and thereby for preventing said fluid from being applied to a substrate; means for applying a sufficiently large electrical charge to said single jet of fluid so as to form a plurality of mutually repellant charged fluid droplets having flight paths which diverge from one another to form a generally conical spray of charged fluid droplets; and means for causing relative movement between said catching means and said conical spray of charged droplets, thereby to prevent said charged droplets from being caught by said catching means and allowing said charged droplets to reach the substrate, when it is desired to deposit fluid on the substrate.
Claim 13
Independent Claim
160 words
An apparatus for applying a fluid in droplet form to a substrate, said apparatus comprising: a source of fluid under pressure; a nozzle in fluid communication with said fluid source for discharging said fluid as a single substantially coherent stream following a single flight path; means, located along said flight path, for catching said fluid and thereby for preventing said fluid from being applied to a substrate; means for applying a sufficiently large electrical charge to said single jet of fluid so as to form a plurality of mutually repellant charged fluid droplets having flight paths which diverge from one another to form a generally conical spray of charged fluid droplets; and means for causing relative movement between said catching means and said conical spray of charged droplets, thereby to prevent said charged droplets from being caught by said catching means and allowing said charged droplets to reach the substrate, when it is desired to deposit fluid on the substrate.
Claim 14
Dependent Claim
27 words
An apparatus as claimed in claim 11, wherein said movement causing means comprises means for deflecting said conical spray of charged droplets away from said catching means.
Claim 15
Dependent Claim
14 words
Apparatus as claimed in claim 12, wherein said deflecting means comprises a deflection electrode.
Claim 16
Dependent Claim
25 words
Apparatus as claimed in claim 13, wherein said deflection electrode is formed as an extension of an electrode forming said means for applying a charge.
Claim 17
Dependent Claim
53 words
Apparatus according to claim 11, in the form of an ink jet apparatus modified to accept a voltage of at least 1000 volts at a charge electrode thereof and having at least one deflection electrode sufficiently spaced from said conical spray of charged droplets that fluid is not deposited on said deflection electrode.
Claim 18
Dependent Claim
14 words
Apparatus as claimed in claim 11, comprising a plurality of nozzles and charging electrodes.
Claim 19
Dependent Claim
32 words
Apparatus as claimed in claim 16, wherein each said nozzle is provided with respective charging and deflection electrodes which are capable of being operated independently of the electrodes serving other said nozzles.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |