Patent US2577240A successfully refreshed from Google Patents.
US3636362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring hole sizes device for measuring hole sizes
Assignee: Individual
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Filing: 1970-08-14
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Granted: 1972-01-18
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Expires: 1990-08-14
Abstract
Abstract A device for measuring the size of apertures in a thin metal sheet having a table that can rotate, preferably in a stepwise manner, and having the sheet to be measured and a standard sheet mounted over openings in the table. A light source is conducted to a movable head and a stationary head. Phototubes in registry with the heads provide two electrical currents, one that is generated from light which has not passed through the sheet and one generated from light that has passed through either the standard or the sheet to be measured. A means for comparing the two currents provides a highly accurate measurement of the hole sizes since the device compensates for changes in light source intensity due to external factors. The device is particularly suited for measuring the size of holes where a high degree of accuracy is required such as in television aperture masks, fine mesh screens and the like.
Inventors
- 👤 James F Beeman
- 👤 Glenn H Roberts
- 👤 Charles W Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:53
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/08; G01B11/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
179 words
A device for measuring the size of apertures in a thin metal sheet comprising: a. a rotatable table having first and second spaced-apart apertures and having means for mounting said thin metal sheet over said first aperture and means for mounting a standard apertured metal sheet over said second aperture, b. means for rotating said table, c. a light source, d. a movable head comprising a light-conducting means located on one side of said table for conducting light from said light source and a phototube for converting the light received into a first electric current, located on the opposing side of said table and in registry with light-conducting means, said head being horizontally and vertically movable, e. means for providing said movement to said first head and maintaining said registry, f. a stationary head external to said table and comprising a light-conducting means for conducting light from said light and a phototube in immediate registry with said light-conducting means for converting the light received into a second electric current, and g. means for comparing said first and second currents.
Claim 2
Independent Claim
179 words
A device for measuring the size of apertures in a thin metal sheet comprising: a. a rotatable table having first and second spaced-apart apertures and having means for mounting said thin metal sheet over said first aperture and means for mounting a standard apertured metal sheet over said second aperture, b. means for rotating said table, c. a light source, d. a movable head comprising a light-conducting means located on one side of said table for conducting light from said light source and a phototube for converting the light received into a first electric current, located on the opposing side of said table and in registry with light-conducting means, said head being horizontally and vertically movable, e. means for providing said movement to said first head and maintaining said registry, f. a stationary head external to said table and comprising a light-conducting means for conducting light from said light and a phototube in immediate registry with said light-conducting means for converting the light received into a second electric current, and g. means for comparing said first and second currents.
Claim 3
Dependent Claim
18 words
A device according to claim 1 wherein said currents generated by said phototubes are fed to a recorder.
Claim 4
Dependent Claim
14 words
A device according to claim 2 wherein said light-conducting means are fiber optic bundles.
Claim 5
Dependent Claim
32 words
A device according to claim 3 wherein a third head is provided on said table to enable measurement of the variation in hole size from center to edges of the apertured sheet.
Claim 6
Dependent Claim
16 words
A device according to claim 4 wherein said apertured metal sheet is a television aperture mask.
Claim 7
Dependent Claim
36 words
A device according to claim 5 wherein said table is rotated in a stepwise manner and said movable head is moved in a horizontal and vertical direction to yield a spiral scan on said aperture mask.
Claim 8
Dependent Claim
16 words
A device according to claim 6 wherein a plurality of standard apertured metal sheets are used.
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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |