US3842894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic means for remote sweep-scanning of a liquid level and for controlling flow to maintain such level
Assignee: Cyprus Amax Minerals Co
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Filing: 1973-01-17
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Granted: 1974-10-22
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Expires: 1993-01-17
Abstract
Abstract The invention contemplates liquid-level control through remote use of a radiation-responsive electrical device optically imaged at a limited region of adjacency between the liquid and a retaining wall, and scanning this region to detect departures from a norm or from a predetermined program of deviation from the norm, the departures being used to correctively adjust flow to maintain a preselected level. The device, described in the context of monitoring a continuous casting of metal, includes a display of a larger field in which the limited region of liquidlevel scanning is also presented, and selectively adjustable means are provided for positioning the limited region within the field, and for displaying the levels at which safety devices come into play to transfer to manual control, without interruption of continuity of flow or casting, in the event that automatic regulation fails to maintain the predetermined level.
Inventors
- 👤 G Southworth
- 👤 P Robbins
- 👤 F Wills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:05
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; B; B22; B22D; B22D11/00; B22D11/16; B22D11/20; B22D11/201; B22D11/204
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
194 words
The method of using a radiation-responsive device to automatically control level of molten material in an upstanding tubular mold open at upper and lower ends, said device having means regulating supply of molten material to the upper end of the mold and extraction of molded product from the lower end of the mold, which method comprises scanning with said radiationresponsive device a selected generally vertically extending and laterally restricted field comprehending only a limited fraction of molten-material surface and adjacent mold-wall surface, such scan being from a fixed location external to and offset from the mold, the scan including a generally vertical recurrent sweep of radiation selected in a spectral-response region for which the molten material and adjacent mold-wall surface produce contrasting levels of electrical signal in said device, whereby an electrical-signal change will occur for each sweep at a time in the sweep reflecting instantaneous level of molten material, utilizing said signal change to generate an electrical control signal indicative of the time in the sweep at which signal change occurs, and utilizing said control signal and therefore the observed time in the sweep to impart a corrective adjustment of said regulating means.
Claim 2
Independent Claim
194 words
The method of using a radiation-responsive device to automatically control level of molten material in an upstanding tubular mold open at upper and lower ends, said device having means regulating supply of molten material to the upper end of the mold and extraction of molded product from the lower end of the mold, which method comprises scanning with said radiationresponsive device a selected generally vertically extending and laterally restricted field comprehending only a limited fraction of molten-material surface and adjacent mold-wall surface, such scan being from a fixed location external to and offset from the mold, the scan including a generally vertical recurrent sweep of radiation selected in a spectral-response region for which the molten material and adjacent mold-wall surface produce contrasting levels of electrical signal in said device, whereby an electrical-signal change will occur for each sweep at a time in the sweep reflecting instantaneous level of molten material, utilizing said signal change to generate an electrical control signal indicative of the time in the sweep at which signal change occurs, and utilizing said control signal and therefore the observed time in the sweep to impart a corrective adjustment of said regulating means.
Claim 3
Dependent Claim
19 words
The method of claim 1, in which the corrective adjustment is used to vary the rate of product extraction.
Claim 4
Dependent Claim
24 words
The method of claim 1, in which the corrective adjustment is used to vary the rate of supply of molten material to the mold.
Claim 5
Dependent Claim
186 words
Continuous-casting apparatus, comprising a vertically oriented mold having a mold wall open at both upper and lower ends, a molten-material supply source including means regulating a continuous supply of molten material to the upper end of said mold, continuously driven product-extraction means beneath the lower end of the mold and regulating the rate of extraction of molded product, and a fixedly mounted electro-optical system connected to one of said means and continuously generating and supplying to said one means a rate-controlling electrical signal, said electro-optical system comprising a scanner oriented to scan a selected generally vertically extending and laterally restricted field comprehending only a limited fraction of molten-material surface and adjacent wall surface, the scan including a generally vertical recurrent sweep of radiation selected in a spectral-response region for which the molten material and adjacent mold-wall surface produce contrasting levels of electrical signal, and means responsive to change in level of said contrasting-level signal for generating an electrical control signal indicative of the time in the sweep at which signal-level change occurs, and means utilizing said control signal in the supply of said rate-controlling electrical signal.
Claim 6
Dependent Claim
186 words
Continuous-casting apparatus, comprising a vertically oriented mold having a mold wall open at both upper and lower ends, a molten-material supply source including means regulating a continuous supply of molten material to the upper end of said mold, continuously driven product-extraction means beneath the lower end of the mold and regulating the rate of extraction of molded product, and a fixedly mounted electro-optical system connected to one of said means and continuously generating and supplying to said one means a rate-controlling electrical signal, said electro-optical system comprising a scanner oriented to scan a selected generally vertically extending and laterally restricted field comprehending only a limited fraction of molten-material surface and adjacent wall surface, the scan including a generally vertical recurrent sweep of radiation selected in a spectral-response region for which the molten material and adjacent mold-wall surface produce contrasting levels of electrical signal, and means responsive to change in level of said contrasting-level signal for generating an electrical control signal indicative of the time in the sweep at which signal-level change occurs, and means utilizing said control signal in the supply of said rate-controlling electrical signal.
Claim 7
Dependent Claim
35 words
Apparatus according to claim 4, in which said last-defined means includes means responding to a change in that time within the sweep period at which the contrasting-level signal changes from one to another contrasting level.
Claim 8
Dependent Claim
19 words
Apparatus according to claim 4, in which said system includes a TV camera positioned to scan said restricted field.
Claim 9
Dependent Claim
41 words
Apparatus according to claim 6, in which said TV camera is oriented to develop a raster of vertically spaced horizontal-line scans, said last-defined means including means responsive to the number of lines-per-frame at which one of the contrasting levels is observed.
Claim 10
Dependent Claim
48 words
Apparatus according to claim 6, in which said TV camera is oriented to develop a raster of laterally spaced vertical-line scans, said last-defined means including means responsive to the time in a given vertical line at which transition occurs from one to the other of the contrasting levels.
Claim 11
Dependent Claim
15 words
Apparatus according to claim 6, in which the TV camera includes a silicon-diode array tube.
Claim 12
Dependent Claim
26 words
Apparatus according to claim 6, in which optical filtering is applied to said camera to optimize contrast in video-signal level corresponding to the respective adjacent surfaces.
Claim 13
Dependent Claim
50 words
Apparatus according to claim 6, in which said camera has a field of view subStantially larger than said restricted field, and in which said system includes gate means operative on the electrical output of said camera to limit to said restricted field the TV-scanned output supplied to said last-defined means.
Claim 14
Dependent Claim
24 words
Apparatus according to claim 11, in which said gate means includes means for selectively adjusting the effective horizontal and vertical extent and location thereof.
Claim 15
Dependent Claim
48 words
Apparatus according to claim 11, in which said system includes a TV display monitor of the entire field of said camera, and mark-generator means responsive to said gate means and connected to said monitor for indicating on the monitor the relative size and location of the restricted field.
Claim 16
Dependent Claim
103 words
Apparatus according to claim 11, including an alarm device operative to indicate an excessively high molten-material level, said device comprising threshold means observing the level of camera video output, said threshold means being set to respond to onset of a level of video signal attributable only to molten material, vertically selectively variable gating means connected to the electrical synchronizing-signal output of said camera to determine an alarm-monitoring vertically high region of the field, said gating and threshold means being conjointly connected and operative to produce the high-level alarm when the threshold condition is achieved within the gated vertically high region of the field.
Claim 17
Dependent Claim
106 words
Apparatus according to claim 11, including an alarm device operative to indicate an excessively low molten-material level, said device comprising threshold means observing the level of camera video output, said threshold means being set to respond to onset of a reduced level of video signal attributable only to absence of molten material, vertically selectively variable gating means connected to the electrical synchronizing-signal output of said camera to determine an alarm-monitoring vertically low region of the field, said gating and threshold means being conjointly connected and operative to produce the low-level alarm when the threshold condition is achieved within the gated vertically low region of the field.
Claim 18
Dependent Claim
102 words
Apparatus according to claim 7, in which said restricted field is limited to a slant aspect of one remote side of the mold wall and adjacent molten material, whereby for a given instantaneous level of molten material the line of intersection between the molten-material surface and the adjacent wall traverses said field along a generally sloping course so that certain horizontal scans will develop a video signal having portions at each of said contrasting levels, and signal-generating means effectively converting the video signal to one only of said levels if that one level occurs during any part of the particular line scan.
Claim 19
Dependent Claim
26 words
Apparatus according to claim 4, in which said last-defined means includes a source of reference-signal voltage, and means comparing said contrasting-level signal with said reference-signal voltage.
Claim 20
Dependent Claim
17 words
Apparatus according to claim 17, and including selectively variable means for controlling said source of reference-signal voltage.
Claim 21
Dependent Claim
40 words
Apparatus according to claim 17, and including modulating means connected to said source and having a cyclic period very substantially exceeding the period of said scanner and operative to periodically modulate the level of reference-signal voltage delivered by said source.
Claim 22
Dependent Claim
23 words
Apparatus according to claim 19, in which said modulating means includes means for selectively varying the amplitude of modulation of said reference-signal voltage.
Claim 23
Dependent Claim
23 words
Apparatus according to claim 19, in which said modulating means includes means for selectively varying the period of modulation of said reference-signal voltage.
Claim 24
Dependent Claim
94 words
Apparatus according to claim 4, in which said mold is one of two such molds and in which said molten-material supply source includes separately controllable means regulating separate continuous supplies of molten material to the respective molds, said electro-optical system being one of two each of which generates a rate-controlling electrical signal for observation of liquid level in a different one of said molds, said electrical signals being respectively connected for supply to said separately controllable means, and reference-voltage means connected in common to the separate contrasting-level responsive means in the respective electro-optical systems.
Claim 25
Dependent Claim
19 words
Apparatus according to claim 22, wherein said last-defined means includes a balanced connection to the respective contrasting-level responsive means.
Claim 26
Dependent Claim
39 words
Apparatus according to claim 22, wherein said product-extraction means is separately provided for each mold, and a common drive control for said respective product-extraction means, said drive control including means summing the output of the respective contrasting-level responsive means.
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) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |