US3841557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating thickness control and fluid handling
Assignee: National Steel Corp
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Filing: 1972-10-06
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Granted: 1974-10-15
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Expires: 1992-10-06
Abstract
Abstract Continuous strip is hot-dip coated and passed between coating control nozzles from which gaseous fluid is projected to form gaseous barriers which wipe excess coating material back into the melt. The width of the gas outlet slot in each nozzle is controlled by thermally expanding at least a portion of the walls of the slot, thereby constricting the slot and thus controlling the flow of gas through the slot, thereby in turn controlling the wiping action of the gaseous barrier on the coating and thus controlling coating thickness. The width of the slot can be selectively controlled at increments in a direction along the length of the slot by a variety of heating means, to produce desired coating thickness at each increment across the width of the strip. The heating means is under remote control and the control system can include structure for displaying slot width and can include automatic control structure. At least a portion of the walls of the slot is of material having a high coefficient of thermal expansion, to enhance the effect of heating. The width of the slot can also be adjusted by cooling at least a portion of the walls of the slot, thereby thermally contracting the walls of the slot and thus enlarging the slot. Cooling can be used to make rapid changes in slot width, to dislodge foreign matter from the slot, to aid the heating means in production of a large temperature differential between intermediate and end portions of the slot, or for other purpose.
Inventors
- 👤 E Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:41
CPC Classifications
C; C23; C23C; C23C2/00; C23C2/14; C23C2/16; C23C2/18; C23C2/20
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
159 words
Coating control apparatus, comprising elongated nozzle means for projecting a gaseous barrier against a coated surface of a continuous substrate to wipe excess molten coating material from the continuous substrate to control the thickness of molten coating on the surface of the continuous substrate, the nozzle means including walls defining linearly extended gas outlet means for projecting gas from the nozzle means, the gas outlet means having length in a direction along the nozzle means, the gas outlet means having width in a direction transverse to the length and transverse to the direction of projection of gas from the nozzle means, heating means contiguous to the gas outlet means for controlling the width of the gas outlet means by thermally expanding at least a portion of the walls of the gas outlet means, and control means for the heating means, the control means including means for operating the heating means from a location spaced remotely from the nozzle means.
Claim 2
Dependent Claim
159 words
Coating control apparatus, comprising elongated nozzle means for projecting a gaseous barrier against a coated surface of a continuous substrate to wipe excess molten coating material from the continuous substrate to control the thickness of molten coating on the surface of the continuous substrate, the nozzle means including walls defining linearly extended gas outlet means for projecting gas from the nozzle means, the gas outlet means having length in a direction along the nozzle means, the gas outlet means having width in a direction transverse to the length and transverse to the direction of projection of gas from the nozzle means, heating means contiguous to the gas outlet means for controlling the width of the gas outlet means by thermally expanding at least a portion of the walls of the gas outlet means, and control means for the heating means, the control means including means for operating the heating means from a location spaced remotely from the nozzle means.
Claim 3
Dependent Claim
36 words
Apparatus as defined in claim 1, in which the heating means includes means for selectively controlling the width of the gas outlet means at increments in a direction along the length of the gas outlet means.
Claim 4
Dependent Claim
18 words
Apparatus as defined in claim 1, the heating means including a plurality of spaced-apart, selectively operable heating elements.
Claim 5
Dependent Claim
13 words
Apparatus as defined in claim 1, the heating means being electrical heating means.
Claim 6
Dependent Claim
48 words
Apparatus as defined in claim 1, at least the portion of the walls of the gas outlet means being of highly expansible material having a coefficient of thermal expansion of at least about 6 X 10 6 inches per inch per degree Fahrenheit between 32* and 212* F.
Claim 7
Dependent Claim
36 words
Apparatus as defined in claim 5, the nozzle means including a pair of die members, one of the die members being of the highly expansible material, the heating means being mounted on the one die member.
Claim 8
Dependent Claim
39 words
Apparatus as defined in claim 1, including cooling means contiguous to the gas outlet means for adjusting the width of the gas outlet means by thermally contracting at least a portion of the walls of the gas outlet means.
Claim 9
Dependent Claim
18 words
Apparatus as defined in claim 7, the cooling means including coolant fluid passage means in the nozzle means.
Claim 10
Dependent Claim
173 words
Coating process, comprising the steps of passing a continuous substrate having opposite surfaces along a travel path through a bath of coating material to form a coating on at least one of the surfaces of the substrate, passing the coating substrate through a coating control zone contiguous to the bath, providing nozzle means in the coating control zone for controlling the thickness of the coating on at least the one surface of the substrate, each nozzle means including walls defining linearly extended gas outlet means, the gas outlet means having length in a direction transverse to the travel path, the gas outlet means having width in a direction along the travel path, projecting a gaseous barrier under pressure from the gas outlet means against the coated substrate to wipe excess coating material into the bath, and controlling the width of the gas outlet means by thermally changing the volume of at least a portion of the walls of the gas outlet means, thereby controlling the flow of gas through the gas outlet means.
Claim 11
Dependent Claim
173 words
Coating process, comprising the steps of passing a continuous substrate having opposite surfaces along a travel path through a bath of coating material to form a coating on at least one of the surfaces of the substrate, passing the coating substrate through a coating control zone contiguous to the bath, providing nozzle means in the coating control zone for controlling the thickness of the coating on at least the one surface of the substrate, each nozzle means including walls defining linearly extended gas outlet means, the gas outlet means having length in a direction transverse to the travel path, the gas outlet means having width in a direction along the travel path, projecting a gaseous barrier under pressure from the gas outlet means against the coated substrate to wipe excess coating material into the bath, and controlling the width of the gas outlet means by thermally changing the volume of at least a portion of the walls of the gas outlet means, thereby controlling the flow of gas through the gas outlet means.
Claim 12
Dependent Claim
14 words
The process of claim 9, in which the volume is thermally changed by heating.
Claim 13
Dependent Claim
15 words
The process of claim 10, in which the volume is also thermally changed by cooling.
Claim 14
Dependent Claim
14 words
The process of claim 9, in which the volume is thermally changed by cooling.
Claim 15
Dependent Claim
25 words
The process of claim 9, in which the volume is thermally changed at increments in a direction along the length of the gas outlet means.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |