Patent US4912410A successfully refreshed from Google Patents.
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
•
Filing: 1988-09-29
•
Granted: 1990-03-27
•
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 19:41
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.
References Cited (Backward Citations)
US3402603A
Cited
US3610024A
Cited
US3528002A
Cited
US3857095A
Cited
US3884076A
Cited
US3818327A
Cited
US4107606A
Cited
US4647855A
Cited
US4742299A
Cited
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 |