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US3764068A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of protecting electrostatic spray nozzles from fouling

Assignee: Air Industrie SA
•
Filing: 1972-06-26
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Granted: 1973-10-09
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Expires: 1992-06-26
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Abstract

Abstract A method of protection of electrostatic projection nozzles against fouling due to the rebounding of a small proportion of the projected ionized particles from the object to be coated with a liquid-coating product comprises essentially the provision of an auxiliary liquid product in addition to the main liquid coating product, the auxiliary liquid being electrically charged to a high voltage of the same sign as the charge of the liquid coating product, and being projected simultaneously with the liquid-coating product towards the front of the projection nozzle and from at least one point external to the central portion of said nozzle so as to oppose and annul the opposite charge on the rebounding particles. The nozzle is provided on its periphery with a plurality of needles formed by fine, hollow tubes with bevelled free extremities which are charged to the electric potential of the same sign as that of the projection nozzle.

Inventors

  • 👤 A Lacchia

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 17:05
CPC Classifications
B; B05; B05B; B05B5/00; B05B5/025; B05B5/03; B05B15/00; B05B15/50

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 80 words
A method of protection against fouling of the nozzles of electrostatic projection apparatus for liquid-coating products, said method comprising essentially the steps of: providing an auxiliary liquid product in addition to said liquid-coating product; projecting said auxiliary liquid simultaneously with said liquid-coating product; electrically charging said auxiliary liquid product to a high voltage; and projecting said auxiliary product towards the front of the projection nozzle and from at least one location external to the central portion of said projection nozzle.
Claim 2
Independent Claim 80 words
A method of protection against fouling of the nozzles of electrostatic projection apparatus for liquid-coating products, said method comprising essentially the steps of: providing an auxiliary liquid product in addition to said liquid-coating product; projecting said auxiliary liquid simultaneously with said liquid-coating product; electrically charging said auxiliary liquid product to a high voltage; and projecting said auxiliary product towards the front of the projection nozzle and from at least one location external to the central portion of said projection nozzle.
Claim 3
Dependent Claim 32 words
A method as claimed in claim 1, in which said auxiliary liquid product is charged electrically with a charge of the same sign as that to which said liquid-coating product is charged.
Claim 4
Dependent Claim 26 words
A method as claimed in claim 1, in which said auxiliary liquid product is a product compatible with the main lqiudi-coating product projected by said nozzle.
Claim 5
Dependent Claim 19 words
A method as claimed in claim 1, in which said auxiliary product is a mixture of gas and liquid.
Claim 6
Dependent Claim 19 words
A method as claimed in claim 1, in which said auxiliary product is a liquid unmixed with any gas.
Claim 7
Dependent Claim 65 words
An electrostatic projection nozzle for a liquid-coating product adapted to carry into effect the method as claimed in claim 1, in which said nozzle is provided, on its periphery, with a plurality of needles constituted by fine and hollow tubes, the extremities of said needles being brought up to an electric potential of the same sign as the electrical high-tension voltage of said projection nozzle.
Claim 8
Dependent Claim 20 words
An electrostatic projection nozzle as claimed in claim 6, in which the free extremities of said hollow needles are bevelled.
Claim 9
Dependent Claim 28 words
An electrostatic projection nozzle as claimed in claim 6, said nozzle comprising a device for the formation and the injection of an auxiliary gas-liquid mixture into said needles.
Claim 10
Dependent Claim 18 words
An electrostatic projection nozzle as claimed in claim 8, in which said injection device comprises a vortex-forming system.
Claim 11
Dependent Claim 18 words
An electrostatic projection nozzle as claimed in claim 8, in which said formation device comprises a convergent-divergent system.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-10-08 1977-04-09 1977-10-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-10-08 1981-04-09 1981-10-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-10-08 1985-04-09 1985-10-09 $7700.00 Window Closed / Lapsed

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