US3600632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Static electricity dishcarge systems
Assignee: TECHNOLOGY UK
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Filing: 1969-12-02
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Granted: 1971-08-17
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Expires: 1989-12-02
Abstract
Abstract Equipment for discharging static electricity from a structure comprises a transducer for measuring the magnitude and polarity of any electrostatic field developed at the surface of the structure, and charge-dispersal apparatus controlled thereby for ejecting electric charges in or on a stream of solid or liquid or frozen liquid particles of greater inertia than atmospheric gas ions. The particles may be formed by condensation in a fastmoving stream of vapor-containing gas. The gas stream may be formed in a duct having a throat and a widening expansion section downstream from the throat constructed so that the gas reached sonic speed at the throat and a speed from 1.3 to 2 times sonic speed in the expansion section. A voltage controlled by the transducer is applied to electrodes in the duct to cause a corona discharge in the gas stream. The invention may be used in aircraft, especially helicopters, and the gas stream may be provided through a duct from an engine of the aircraft.
Inventors
- 👤 Alfred William Bright
- 👤 Brian Makin
- 👤 Michael Edward Rogers
- 👤 Bruce Robert Whewell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:14
CPC Classifications
H; H05; H05F; H05F3/00; B; B64; B64D; B64D45/00; B64D45/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
147 words
A system for discharging undesirable static electricity from a structure, comprising transducer means for providing a signal or signals indicative of the magnitude and polarity of any electrostatic field gradient developed at the surface of the structure, means for providing a stream of vapor-containing gas travelling at or near the speed of sound, charge injection means for injecting electric charges into the said stream by a corona discharge, and expansion means for making the said stream expand sufficiently to cause condensation of vapor therein, so as to form particles or droplets in the stream having greater inertia than ions of atmospheric gases, the said charge injection means being connected to the said transducer means and responsive to the said signal or signals for controlling the ejection of electrical charges from the structure in or on the said stream so as to reduce the said electrostatic field gradient.
Claim 2
Independent Claim
147 words
A system for discharging undesirable static electricity from a structure, comprising transducer means for providing a signal or signals indicative of the magnitude and polarity of any electrostatic field gradient developed at the surface of the structure, means for providing a stream of vapor-containing gas travelling at or near the speed of sound, charge injection means for injecting electric charges into the said stream by a corona discharge, and expansion means for making the said stream expand sufficiently to cause condensation of vapor therein, so as to form particles or droplets in the stream having greater inertia than ions of atmospheric gases, the said charge injection means being connected to the said transducer means and responsive to the said signal or signals for controlling the ejection of electrical charges from the structure in or on the said stream so as to reduce the said electrostatic field gradient.
Claim 3
Dependent Claim
37 words
A system as claimed in claim 1 wherein the said means for providing the said stream of gas comprises a duct for leading said stream of gas from a gas turbine engine to said charge injection means.
Claim 4
Dependent Claim
52 words
A system as claimed in claim 1 and wherein the said means for providing the said stream of gas comprises a duct which tapers to a throat and is constructed so that in operation the said stream of gas will reach the speed of sound within the throat of the said duct.
Claim 5
Dependent Claim
73 words
A system as claimed in claim 3 and wherein the said expansion means comprises a widening expansion section of the said duct downstream from the throat thereof, constructed so that when the said stream of gas reaches the speed of sound within the throat of the duct, it will reach a speed in the range from 1.3 times the speed of sound to twice the speed of sound within the said expansion section.
Claim 6
Dependent Claim
93 words
A system as claimed in claim 3 and wherein the said charge injection means comprises at least one sharp-pointed electrode mounted with its point within the duct, another electrode insulated from the said at least one sharp-pointed electrode, and means for applying a voltage between the other electrode and the sharp-pointed electrode sufficient for causing a corona discharge from the said point and within the said stream of gas, the said voltage being controlled according to the said signal or signals indicative of the magnitude and polarity of the said electrostatic field gradient.
Claim 7
Dependent Claim
94 words
A system as claimed in claim 3 and wherein the said charge injection means comprises at least one sharp-edged electrode mounted with a sharp edge within the duct, another electrode insulated from the said at least one sharp-edged electrode, and means for applying a voltage between the other electrode and the sharp-edged electrode sufficient for causing a corona discharge from the said sharp edge within the said stream of gas, the said voltage being controlled according to the said signal or signals indicative of the magnitude and polarity of the said electrostatic field gradient.
Claim 8
Dependent Claim
25 words
A system as claimed in claim 1 and wherein the said transducer means comprises a rotating-vane electrometer and a detector circuit incorporating a logarithmic amplifier.
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) | 1974-08-16 | 1975-02-15 | 1975-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-16 | 1979-02-15 | 1979-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-16 | 1983-02-15 | 1983-08-17 | $7700.00 | Window Closed / Lapsed |