US4563977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic coating plant
Assignee: Spengler Electronic AG
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Filing: 1984-08-28
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Granted: 1986-01-14
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Expires: 2004-08-28
Abstract
Abstract Inside the enclosing wall (1) of the electrostatic coating plant for applying dry or wet color coatings to electrically conductive surfaces of articles (2) set up in an insulated position is located an electrostatically chargeable curtain (9), the charge polarity of which is the same as that of the spraying gun (7) used for the coating operation. The article (2) set up in an insulated position is supplied with opposite polarity, which is necessary for the electrostatic coating, by an inductor arrangement (16) arranged above the article (2), the inductor arrangement (16) applying an electrostatic field produced by means of a peak inductor (19) to an electrically conducting layer (18), which is located on the rear of a casing piece (17) made of insulating material. The charge field radiated from the surface of the casing piece (17) brings the article (2) to be coated, suspended beneath the casing piece (17), to a potential at which the material particles located in the spraying jet (8) of the spraying gun ( 7) strike both the front and rear surface sections with approximately uniform distribution. The achieved electrostatic guidance of the coating material particles enables both an optimum utilization of the coating material and a speeded-up operating function of the coating plant.
Inventors
- 👤 Walter Spengler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:37
CPC Classifications
B; B05; B05B; B05B5/00; B05B5/08; B05D; B05D1/00; B05D1/02; B05D1/04; B05D1/06; B05D2202/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
179 words
An electrostatic coating plant for applying dry or wet surface coatings to articles having an electrically conducting surface, said apparatus comprising an enclosing wall defining an enclosed treatment area, a spraying gun for spraying electrostatically charged particles of a predetermined polarity into the treatment area, a support device electrically insulated from said enclosing wall for supporting an article to be coated in said treatment area within the spraying range of said gun, inductor means cooperating with said support device for charging the article which is supported thereon with an electrostatic potential of a polarity opposite that of the electrostatically charged particles from said spraying gun, at least one electrically conducting curtain electrically insulated from said enclosing wall and positioned in said treatment area opposite said spraying gun and behind the article to be coated, and means for charging said at least one curtain with an electrostatic potential of the same polarity as the electrostatically charged particles from said spraying gun, whereby particles which may be sprayed past the article are reflected back onto the rear side of the article.
Claim 2
Dependent Claim
179 words
An electrostatic coating plant for applying dry or wet surface coatings to articles having an electrically conducting surface, said apparatus comprising an enclosing wall defining an enclosed treatment area, a spraying gun for spraying electrostatically charged particles of a predetermined polarity into the treatment area, a support device electrically insulated from said enclosing wall for supporting an article to be coated in said treatment area within the spraying range of said gun, inductor means cooperating with said support device for charging the article which is supported thereon with an electrostatic potential of a polarity opposite that of the electrostatically charged particles from said spraying gun, at least one electrically conducting curtain electrically insulated from said enclosing wall and positioned in said treatment area opposite said spraying gun and behind the article to be coated, and means for charging said at least one curtain with an electrostatic potential of the same polarity as the electrostatically charged particles from said spraying gun, whereby particles which may be sprayed past the article are reflected back onto the rear side of the article.
Claim 3
Dependent Claim
26 words
Electrostatic coating plant as claimed in claim 1 wherein said inductor means is located substantially directly above the article which is supported by said support device.
Claim 4
Dependent Claim
53 words
Electrostatic coating plant as claimed in claim 1, wherein said at least one curtain contains a material which is impenetrable to the particles emerging from the spraying gun, and at least the surface facing toward the article to be coated is provided with an electrically insulating material as a protection against accidental contact.
Claim 5
Dependent Claim
38 words
Electrostatic coating plant as claimed in claim 1, wherein said at least one curtain is of such dimensions and so positioned relative to said spraying gun as to extend at least over the working area of said gun.
Claim 6
Dependent Claim
28 words
Electrostatic coating plant as claimed in claim 1, wherein the electrically conducting material of said at least one curtain is connected to a voltage via a resistive contact.
Claim 7
Dependent Claim
39 words
Electrostatic coating plant as claimed in claim 1, wherein said means for charging said at least one curtain comprises an inductor device having discharging peaks facing toward but out of electrically conducting contact with said at least one curtain.
Claim 8
Dependent Claim
29 words
Electrostatic coating plant as claimed in claim 1, wherein said at least one curtain is provided with a sensor which monitors the charge field strength delivered by the curtain.
Claim 9
Dependent Claim
50 words
Electrostatic coating plant as claimed in claim 2, wherein the inductor means above the article to be coated has a casing facing toward the article to be coated, with an electrically insulating coating applied to at least the surface directed downstream, and an electrically conducting layer carried by said casing.
Claim 10
Dependent Claim
44 words
Electrostatic coating plant as claimed in claim 8, wherein the inductor means is divided into two halves located on opposite sides of the support device and symmetrical relative to the support device each of the two halves including an inductor having a discharging peak.
Claim 11
Dependent Claim
44 words
Electrostatic coating plant as claimed in claim 8, wherein the inductor means has a one-piece casing firmly connected to the support device, the casing having an electrically through-connecting, conducting layer and a peak inductor electrostatically charging the said layer and arranged above the casing.
Claim 12
Dependent Claim
73 words
Electrostatic coating plant as claimed in claim 1 wherein said support device for the article to be coated is mounted for movement for transporting the article along a predetermined path of travel past said spraying gun, and said coating plant includes an ionizing device located downstream from the treatment area for neutralizing any charge which may still be present on the coated article after the coated article passes downstream from said treatment area.
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) | 1989-01-13 | 1989-07-15 | 1990-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-13 | 1993-07-15 | 1994-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-13 | 1997-07-15 | 1998-01-14 | $7700.00 | Window Closed / Lapsed |