US3901185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating method with precure and apparatus therefor
Assignee: ELECTROSTATIC EQUIPMENT CORP
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Filing: 1974-02-14
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Granted: 1975-08-26
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Expires: 1994-02-14
Abstract
Abstract An apparatus and method are provided for producing a coating of heat fusible resinous material upon only a portion of a workpiece. The resinous material is deposited upon the workpiece as electrostatically charged particles. One zone of the workpiece is heated to cause fusion and cohesion of the particles while a second zone is simultaneously cooled to prevent such a result and to thereby facilitate removal of particles from the cooled zone. The apparatus and method are particularly adapted for producing thermoplastic coatings upon armature rotors for electric motors.
Inventors
- 👤 William C Goodridge
- 👤 Donald J Gillette
- 👤 William P English
- 👤 G Mark Minckler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:36
CPC Classifications
B; B05; B05C; B05C19/00; B05C19/02; B05C19/025; B05B; B05B16/00; B05B16/90; B05B16/95
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
226 words
In an apparatus for producing a unified, adherent coating of heat-fusible resinous material upon only a portion of a workpiece having proximate first and second zones in heat-conductive contact with one another, the combination comprising: a. a chassis; b. means on said chassis for producing a cloud of electrostatically charged solid particles of resinous material; c. a precuring unit on said chassis including means for heating the first zone of the workpiece to be coated and means for simultaneously cooling the second zone thereof; and d. means for carrying the workpiece along a travel path through said cloud-producing means and said precuring unit, said heating and cooling means being so disposed as to enable heating of the first zone of the workpiece to a relatively high temperature above ambient while the second zone thereof is simultaneously maintained at a relatively low temperature substantially below said relatively high temperature, so that the workpiece may be exposed to the charged particles from said cloud-producing means with the workpiece charged effectively opposite to the paRticles to cause a layer thereof to deposit upon the workpiece, said heating means causing at least partial fusion and coherence of the particles at the first zone and said cooling means substantially preventing fusion and coherence of particles at the second zone thereof, removal of the particles from the second zone thereby being facilitated.
Claim 2
Dependent Claim
226 words
In an apparatus for producing a unified, adherent coating of heat-fusible resinous material upon only a portion of a workpiece having proximate first and second zones in heat-conductive contact with one another, the combination comprising: a. a chassis; b. means on said chassis for producing a cloud of electrostatically charged solid particles of resinous material; c. a precuring unit on said chassis including means for heating the first zone of the workpiece to be coated and means for simultaneously cooling the second zone thereof; and d. means for carrying the workpiece along a travel path through said cloud-producing means and said precuring unit, said heating and cooling means being so disposed as to enable heating of the first zone of the workpiece to a relatively high temperature above ambient while the second zone thereof is simultaneously maintained at a relatively low temperature substantially below said relatively high temperature, so that the workpiece may be exposed to the charged particles from said cloud-producing means with the workpiece charged effectively opposite to the paRticles to cause a layer thereof to deposit upon the workpiece, said heating means causing at least partial fusion and coherence of the particles at the first zone and said cooling means substantially preventing fusion and coherence of particles at the second zone thereof, removal of the particles from the second zone thereby being facilitated.
Claim 3
Dependent Claim
51 words
The apparatus of claim 1 wherein said heating and cooling means extend along substantially the same length of said travel path, said cooling means comprising an element having a cooled support surface upon which the second zone of the workpiece rests in heat transfer contact during movement through said precuring unit.
Claim 4
Dependent Claim
38 words
The apparatus of claim 1 additionally including cleaning means positioned on said chassis along said travel path downstream of said precuring unit for effecting the removal of particles of resinous material from the second zone of the workpiece.
Claim 5
Dependent Claim
58 words
The apparatus of claim 3 additionally including post heating means positioned along said travel path downstream of said cleaning means, said post heating means being adapted to fully heat the entire workpiece so as to melt the remaining particles of resinous material and produce from them a unified and adherent coating on the first zone of the workpiece.
Claim 6
Dependent Claim
43 words
The apparatus of claim 1 additionally including particle removal means positioned on said chassis between said cloud-producing means and said precuring unit to effect at least a preliminary removal of particles of resinous material from at least the second zone of the workpiece.
Claim 7
Dependent Claim
129 words
The apparatus of claim 1 wherein said apparatus is particularly adapted for producing a coating upon a generally cylindrical article having a central portion providing the first zone thereof and end portions extending axially from either side of the central portion together providing the second zone of the article, said cooling means of said precuring unit comprising two elements each having a cooled surface extending along an opposite side of said travel path and being adapted to support and thereby cool one of the end portions of the article during movement thereof along said travel path through said unit, said heating means comprising a heating element extending along said travel path and lying generally between said cooled surfaces to heat the central portion of the article during such movement.
Claim 8
Dependent Claim
46 words
The apparatus of claim 2 wherein said cooling means additionally includes an overlying element having a cooled lower surface extending substantially parallel and in spaced alignment over said support surface to provide a convective cooling effect upon the second zone of the workpiece during passage therebeneath.
Claim 9
Dependent Claim
70 words
The apparatus of claim 7 wherein said carrying means comprises a conveyor including an upstanding element for supporting an article extending transversely across said travel path with the first and second zones of the article lying on opposite sides thereof, said conveyor element cooperating with said overlying element of said cooling means to provide a shield against heat flow by radiation and convection to the second zone of the article.
Claim 10
Dependent Claim
62 words
The apparatus of claim 1 wherein said precuring unit includes a base providing at least in part said cooling means thereof, said base having an elongated channel extending therein along said travel path through which at least a portion of the workpiece passes, the surfaces of said base defining said channel being cooled to provide a cooling effect partially about said workpiece.
Claim 11
Dependent Claim
38 words
The apparatus of claim 9 wherein said heating means comprises a heating element supported by a cover member movably mounted upon said chassis for displacement from a normal position over said travel path to a position outwardly therefrom.
Claim 12
Dependent Claim
64 words
The apparatus of claim 10 wherein said cooling means additionally includes an overlying element supported by said cover member and having a cooled lower surface, with said cover in said normal position thereof said lower surface extending substanTially parallel to and in spaced alignment over said support surface to provide a convective cooling effect upon the second zone of the workpiece during passage therebeneath.
Claim 13
Dependent Claim
70 words
The apparatus of claim 1 wherein said cloud-producing means includes an electrostatic cloud chamber, said chamber comprising a receptacle having means for producing a fluidized bed of charged particles including a gas-permeable plate extending thereacross in a generally horizontal intermediate plane spaced above the bottom wall thereof to define a plenum chamber therebelow and having electrode means extending thereacross for electrostatically charging particles of solid resinous material passing proximate thereto.
Claim 14
Dependent Claim
122 words
The apparatus of claim 12 additionally including a particulate material reservoir having feed means communicating with said cloud chamber, wherein said electrode means spans a lesser area than said plate to provide an electrode-free vertical corridor within said receptacle through which particles of the resinous material may pass without acquiring a significant charge, said receptacle also including a device for sensing the level of the bed of particles therewithin to which said feed means is responsive to convey resinous material from said reservoir to said chamber when said bed level falls below a preselected height, said sensing device being positioned within said vertical corridor over said permeable plate to minimize the effect of electrostatic charging upon the sensed level of the bed.
Claim 15
Dependent Claim
53 words
The apparatus of claim 13 wherein said electrode is a generally planar, grid-like structure and is disposed adjacent the upper surface of said gas-permeable plate, said electrode and plate being substantially coextensive except at one area of said plate over which said electrode does not extend to thereby provide said electrode-free vertical corridor.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |