US3617872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic thickness gauge with a gas-supported sensor and a suction source in the base
Assignee: Indev Inc
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Filing: 1969-10-06
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Granted: 1971-11-02
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Expires: 1989-10-06
Abstract
Abstract In an apparatus for measuring the thickness of material including a magnetic sensor forming an incomplete magnetic circuit, a gas source, structure defining a gas-confining chamber in communication with said gas source providing a gas cushion on the top surface of said material for supporting the sensor a fixed distance above the top surface of said material, and readout means for producing a signal dependent on relative vertical sensor movement, the improvement comprising material support structure including a supporting member formed of magnetic material to complete a magnetic circuit with the sensor, and providing a flat supporting surface located opposite the sensor and contacting the underside of the material, a suction source, and structure providing communication between the suction source and the underside of the material adjacent said flat supporting surface to maintain the underside of the material flush against the flat supporting circuit such that parameters of the magnetic circuit due to the distance between the sensor and the magnetic supporting member are dependent solely on the thickness of the material.
Inventors
- 👤 John J Horn
- 👤 George E Corneau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:34
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; G01B7/10; G01B7/107; G01B2210/00; G01B2210/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
208 words
In an apparatus for measuring the thickness of material, said apparatus including a magnetic sensor forming an incomplete magnetic circuit, a gas source, structure defining a gasconfining chamber in communication with said gas source providing a gas cushion on the top surface of said material for supporting said sensor a fixed distance above and out of contact with said top surface, and readout means for producing a signal dependent on relative vertical sensor movements the improvement comprising material support structure including a supporting member formed of magnetic material to complete a magnetic circuit with said sensor and providing a flat supporting surface located opposite said sensor and contacting the underside of said material, a suction source, and structure providing communication between said suction source and the underside of said material through said flat supporting surface to apply suction at least to material located over an area of said flat supporting surface inclusive of the projected area of said gas-confining chamber upon said flat supporting surface in order to maintain said material flush against said area of said flat supporting surface, such that parameters of said magnetic circuit due to the distance between said senSor and said magnetic supporting member are dependent solely on the thickness of said material.
Claim 2
Dependent Claim
208 words
In an apparatus for measuring the thickness of material, said apparatus including a magnetic sensor forming an incomplete magnetic circuit, a gas source, structure defining a gasconfining chamber in communication with said gas source providing a gas cushion on the top surface of said material for supporting said sensor a fixed distance above and out of contact with said top surface, and readout means for producing a signal dependent on relative vertical sensor movements the improvement comprising material support structure including a supporting member formed of magnetic material to complete a magnetic circuit with said sensor and providing a flat supporting surface located opposite said sensor and contacting the underside of said material, a suction source, and structure providing communication between said suction source and the underside of said material through said flat supporting surface to apply suction at least to material located over an area of said flat supporting surface inclusive of the projected area of said gas-confining chamber upon said flat supporting surface in order to maintain said material flush against said area of said flat supporting surface, such that parameters of said magnetic circuit due to the distance between said senSor and said magnetic supporting member are dependent solely on the thickness of said material.
Claim 3
Dependent Claim
30 words
The apparatus of claim 1 wherein said supporting member includes a plurality of apertures therethrough extending between said suction source and the underside of said material providing said communication therebetween.
Claim 4
Dependent Claim
14 words
The apparatus of claim 2 wherein said apertures are arranged to include said area.
Claim 5
Dependent Claim
27 words
The apparatus of claim 3 wherein said perforations are peripherally spaced about an imaginary circle enclosing the projected area of said gas-confining chamber on said supporting surface.
Claim 6
Dependent Claim
33 words
The apparatus of claim 4 wherein said gas-confining chamber is of annular construction, and said perforations are located entirely outside of the projected annular area of said gas-confining chamber on said supporting surface.
Claim 7
Dependent Claim
61 words
The apparatus of claim 1 wherein said material is in the form of a continuous sheet travelling between said sensor and said support structure, and said suction source is constructed to apply suction through said perforations sufficient to maintain the said underside of said web flush against said supporting surface, while permitting travel of said sheet along said flat supporting surface.
Claim 8
Dependent Claim
65 words
The apparatus of claim 6 wherein said sensor and said material support structure are each mounted on a carriage, and said carriage is arranged for selected movement across the width of said sheet transverse to the travelling direction thereof, whereby the thickness of material sheets of width greater than the width of said flat supporting surface may be measured at preselected zones across said width.
Claim 9
Dependent Claim
39 words
The apparatus of claim 7 including a flexible suction hose between said material support structure and said suction source, said hose constructed to permit transverse movement of said support structure on said carriage across the width of said sheet.
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) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |