Patent US3608823A successfully refreshed from Google Patents.
US3608823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the electrostatic coating of objects with atomized solids particles
Assignee: Gema Switzerland GmbH
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Filing: 1970-06-24
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Granted: 1971-09-28
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Expires: 1990-06-24
Abstract
Abstract A spray gun for electrostatic coating of objects with atomized solid particles comprises a tube of electrically insulating material, the free end of the tube supporting an atomizer for the coating material and the other end being connected to conveying means for supplying coating material by means of a propellant gas stream. A high-voltage generator and electrodes are provided for the electric charging of the coating material and for maintaining a high-voltage field between the gun and the object to be coated. A plurality of electrodes are disposed on the internal wall of said electrically insulating tube and are connected to potentials of different amplitudes for producing corona discharge within the tube. The electrodes preferably are formed as spikes of tungsten successively projecting from the internal wall of the tube in the direction of flow of the propellent gas-coating material mixture, each electrode being connected to one stage of a voltage divider or voltage multiplier circuit so that the successive electrodes have an increasing potential relative to a reference potential.
Inventors
- 👤 Karl Buschor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:01
CPC Classifications
B; B05; B05B; B05B5/00; B05B5/025; B05B5/053; B05B5/0531; B05B5/03; B05B5/032; B05B5/16; B05B5/1691; H; H02; H02M; H02M7/00; H02M7/02; H02M7/04; H02M7/06; H02M7/10; H02M7/103; H02M7/106
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
24 words
Apparatus according to claim 1, in which each of said electrodes are connected to one step of a voltage divider or voltage multiplier circuit.
Claim 2
Dependent Claim
34 words
Apparatus according to claim 2, in which said atomizer disposed on said insulating tube is provided with a supplementary electrode which is connected to one step of the voltage divider or voltage multiplier circuit.
Claim 3
Dependent Claim
18 words
Apparatus according to claim 3, in which said supplementary electrode is embedded in its entirety in insulating material.
Claim 4
Dependent Claim
25 words
Apparatus according to claim 3, in which the supplementary electrode is covered with insulating material with the exception of a small zone of its surface.
Claim 5
Dependent Claim
24 words
Apparatus according to claim 2, in which atomizers or supplementary electrodes and atomizers with supplementary electrodes may be optionally attached to the insulating tube.
Claim 6
Dependent Claim
46 words
Apparatus according to claim 1, in which the electrodes are disposed on the front end of the insulating tube which supports or forms the atomizer and are disposed at a distance from the tube discharge opening which is no greater than the diameter of the opening.
Claim 7
Dependent Claim
41 words
Apparatus according to claim 7, in which the electrodes are electrically combined into two groups of which the first electrode group is connected to the output of said high-voltage generator and the second electrode group is connected to a lower potential.
Claim 8
Dependent Claim
18 words
Apparatus according to claim 8, in which the second electrode group is connected to earth via a resistor.
Claim 9
Dependent Claim
26 words
Apparatus according to claim 8, in which each of the two electrode groups is connected to one step of a voltage divider or voltage multiplier circuit.
Claim 10
Dependent Claim
44 words
Apparatus according to claim 10 having a voltage multiplier circuit composed of two columns of serially connected capacitors and rectifiers, in which each of the two electrode groups is connected to one column of capacitors and each column of capacitors contains a damping resistor.
Claim 11
Dependent Claim
21 words
Apparatus according to claims 2, in which the electrodes are spikes which project from the internal wall of the insulating tube.
Claim 12
Dependent Claim
14 words
Apparatus according to claim 12, in which the spike-shaped electrodes are constructed of tungsten.
Claim 13
Dependent Claim
21 words
Apparatus according to claim 12, in which the spike electrodes are disposed along at least one helix on the insulating tube.
Claim 14
Dependent Claim
51 words
Apparatus according to claim 12, in which the spike-shaped electrodes are disposed in a plane which is perpendicular to the axis of the insulating tube and are electrically interconnected so that the even-numbered series of electrodes forms one electrode group and the odd-numbered series of electrodes forms the other electrode group.
Claim 15
Dependent Claim
29 words
Apparatus according to claim 2, in which the step circuit elements of the voltage divider or voltage multiplier circuit and the damping resistors are disposed on the insulating tube.
Claim 16
Dependent Claim
26 words
Apparatus according to claim 16, in which the resistors of the voltage divider circuit are constructed in annular form and are pushed upon the insulating tube.
Claim 17
Dependent Claim
23 words
Apparatus according to claim 16, in whicH the voltage divider is a tubular resistor, individual positions of which are connected to the electrodes.
Claim 18
Dependent Claim
27 words
Apparatus according to claim 1, having a high-voltage generator containing a voltage converter, in which the voltage converter is disposed in a housing on the insulating tube.
Claim 19
Dependent Claim
58 words
Apparatus according to claim 19, for use as hand spraygun, in which a housing attached to the insulating tube is constructed as gun handle for accommodating the voltage converter, the gun handle containing a switch for switching the voltage converter on or off, said converter being connected to the power supply source by means of a low-voltage cable.
Claim 20
Dependent Claim
32 words
Apparatus according to claim 20, in which conveying means having a material supply hopper and connected via a hose line to the supply of propellant gas, is mounted on the insulating pipe.
References Cited (Backward Citations)
US2995393A
Cited
US3408985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |