US3585395A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of hole size in filters by measuring the amount of radiation passing through holes and correspondingly controlling speed of filter moving through etching bath
Assignee: General Electric Co
•
Filing: 1966-09-06
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Granted: 1971-06-15
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Expires: 1986-09-06
Abstract
Abstract A method and an apparatus for continuously manufacturing a filter web including continuously measuring and controlling hole size are disclosed. This system basically includes an etching tank through which a fission-fragment irradiated web is fed to form holes therein, a radiation means on one side of the etched web and a radiation detector on the other side which is adjusted to measure only radiation which at least partially passes through holes in the web and means responsive to said measurement to adjust web residence time in the etchant to maintain hole size in the desired range.
Inventors
- 👤 Maurice A Robkin
- 👤 Charles R Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:57
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/08; G01N15/088; G01N23/00; G01N23/02; G01N23/06; G01N23/16; Y; Y10; Y10S; Y10S55/00; Y10S55/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
24 words
The apparatus defined in claim 1 in which the radiation source emits alpha particles, and the radiation measuring means is sensitive to alpha particles.
Claim 2
Dependent Claim
20 words
The apparatus defined in claim 1 in which the holes in the material have diameters less than about 10 microns.
Claim 3
Dependent Claim
32 words
The apparatus defined in claim 1, in which the sheet of material is opaque to light, and in which the radiation source emits light and the radiation-measuring means is sensitive to light.
Claim 4
Independent Claim
113 words
A method of filter hole size measurement and control which comprises: a. passing a continuous web of fission fragment irradiated dielectric material through an etching bath wherein holes are formed through said web along fission fragment paths; hole size being a function of residence time in said bath; b. rinsing and drying said web; c. irradiating said web with a known amount of radiation; d. measuring the amount of radiation passing at least partially through the holes; and e. varying the residence time of said web in said etching bath by varying the speed of a web drive means in accordance with said measured radiation to maintain hole size within the desired range.
Claim 5
Dependent Claim
13 words
The method defined in claim 5 in which the radiation is alpha radiation.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |