US4912410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring the thickness of an electrically non-conductive material on a metallic base
Assignee: BNF Metals Technology Centre
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Filing: 1988-09-29
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Granted: 1990-03-27
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Expires: 2008-09-29
Abstract
Abstract An apparatus for measuring the thickness of a coating of, for example, paint or other electrically non-conductive material on a metallic base comprises a sensor head housing an electrical measuring coil and supported above the coating on a cushion of air. The air is supplied at a constant predetermined pressure to nozzles carried by the sensor head, and a constant force urging the sensor head towards the surface of the material is yieldably applied to the sensor head through a spring.
Inventors
- 👤 Edward J. Morley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:42
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; G01B7/10; G01B7/105; G01B5/00; G01B5/0002
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
An apparatus for measuring the thickness of an electrically non-conductive material on an electrically conductive base, said apparatus comprising: a support; a sensor head having a surface for facing the electrically non-conductive material, said sensor head including therein an electrical measuring coil for measuring the thickness of the electrically non-conductive material; a universal connection means between said support and said sensor head for enabling universal pivoting movement of said sensor head relative to said support; an air chamber in said sensor head; a plurality of air nozzles in said sensor head opening onto said surface of said sensor head and communicating with said air chamber; means for supplying air at a predetermined pressure to said air chamber, thus supplying said nozzles with air to support said sensor head on a cushion of air over the surface of the electrically non-conductive material; and means connected to said universal connection means for yieldably urging said sensor head towards the surface of the electrically non-conductive material with a constant force.
Claim 2
Independent Claim
167 words
An apparatus for measuring the thickness of an electrically non-conductive material on an electrically conductive base, said apparatus comprising: a support; a sensor head having a surface for facing the electrically non-conductive material, said sensor head including therein an electrical measuring coil for measuring the thickness of the electrically non-conductive material; a universal connection means between said support and said sensor head for enabling universal pivoting movement of said sensor head relative to said support; an air chamber in said sensor head; a plurality of air nozzles in said sensor head opening onto said surface of said sensor head and communicating with said air chamber; means for supplying air at a predetermined pressure to said air chamber, thus supplying said nozzles with air to support said sensor head on a cushion of air over the surface of the electrically non-conductive material; and means connected to said universal connection means for yieldably urging said sensor head towards the surface of the electrically non-conductive material with a constant force.
Claim 3
Dependent Claim
30 words
The apparatus as set forth in claim 1, and further comprising: means for enabling movement of said support in a lateral traverse parallel to said surface of said sensor head.
Claim 4
Dependent Claim
26 words
The apparatus as set forth in claim 1, wherein: said means for yieldably urging said sensor head towards the surface of the material comprises a weight.
Claim 5
Dependent Claim
26 words
The apparatus as set forth in claim 1, wherein: said means for yieldably urging said sensor head toward the surface of the material comprises a spring.
Claim 6
Dependent Claim
74 words
The apparatus as set forth in claim 4, wherein: said means for yieldably urging comprises a lever arm connected between said support and said universal connection means, said spring yieldably urging said sensor head toward the surface of the material by engaging said lever arm at a point between said sensor head and said support so as to apply to said sensor head only a predetermined proportion of the force exerted by the spring.
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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) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |