US4427976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture sensor
Assignee: Coal Industry Patents Ltd
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Filing: 1979-08-22
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Granted: 1984-01-24
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Expires: 1999-08-22
Abstract
Abstract This invention relates to a device for sensing moisture on a metal surface such as a brake path. Since the presence of moisture on a brake path causes inefficient working of the brake, it is necessary to test for moisture. Originally this was done by hand. The present invention provides a device which can test for moisture automatically. The device comprises a pair of contacts urged against an electrically conducting surface. One contact is covered by a strip of material, for instance paper, which is an insulator when dry and a conductor when moist. If moisture is present an electrical circuit comprising the surface, the moist material and the two contacts is completed activating an alarm. The material may be salt impregnated and the contacts may be moveable over the surface. The device is for use in testing for moisture on the braking surface of colliery winding installations.
Inventors
- 👤 Peter M. Lord
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:35
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/121
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
169 words
A device for sensing moisture on an electrically conductive surface comprising a supporting member positioned above the surface, first and second electrical contacts mounted on the supporting member and electrically insulated from one another, material which is electrically conductive when moist and electrically insulating when dry, material location means mounted on the supporting member for positioning the material between the first contact and the surface, bias means for biasing the supporting member toward the surface so that the piece of material is trapped between the first contact and the surface and the second contact is brought into direct electrical contact with the surface, and electrical circuit means for applying voltage across the two contacts, said electrical circuit means comprising means for indicating when a current is flowing between the two contacts, whereby if the surface is moist, the piece of material is moistened and becomes electrically conductive, and the electrical circuit indicates that a current is flowing between the contacts, thereby indicating the presence of moisture on the surface.
Claim 2
Independent Claim
169 words
A device for sensing moisture on an electrically conductive surface comprising a supporting member positioned above the surface, first and second electrical contacts mounted on the supporting member and electrically insulated from one another, material which is electrically conductive when moist and electrically insulating when dry, material location means mounted on the supporting member for positioning the material between the first contact and the surface, bias means for biasing the supporting member toward the surface so that the piece of material is trapped between the first contact and the surface and the second contact is brought into direct electrical contact with the surface, and electrical circuit means for applying voltage across the two contacts, said electrical circuit means comprising means for indicating when a current is flowing between the two contacts, whereby if the surface is moist, the piece of material is moistened and becomes electrically conductive, and the electrical circuit indicates that a current is flowing between the contacts, thereby indicating the presence of moisture on the surface.
Claim 3
Dependent Claim
30 words
A device according to claim 1 wherein the supporting member is provided with second bias means for biasing one of the contacts toward the surface independently of the other contact.
Claim 4
Dependent Claim
22 words
A device according to claim 1 wherein the supporting member is provided with means for moving the supporting member across the surface.
Claim 5
Dependent Claim
36 words
A device according to claim 3 wherein the moving means is provided with means for raising the supporting member upwardly from the surface at the end of a movement of the supporting member across the surface.
Claim 6
Dependent Claim
13 words
A device according to claim 4 wherein the raising means comprises a guide,
Claim 7
Dependent Claim
55 words
an element pivotally connected to the supporting member and mounted for reciprocating movement on said guide, and an abutment positioned on said guide to engage a projection formed on the supporting member at the end of said movement of the supporting member across the surface to urge the supporting member to pivot about the element.
Claim 8
Dependent Claim
55 words
an element pivotally connected to the supporting member and mounted for reciprocating movement on said guide, and an abutment positioned on said guide to engage a projection formed on the supporting member at the end of said movement of the supporting member across the surface to urge the supporting member to pivot about the element.
Claim 9
Dependent Claim
42 words
A device according to claim 1 wherein the material is in the form of an elongated strip which is wound onto a pair of reels, the supporting member being provided with means for reeling the material from one reel to the other.
Claim 10
Dependent Claim
100 words
A device according to claim 6 wherein one of the reels is provided with a ratchet, and the reeling means is provided with a lever having first and second ends and being pivotally mounted between said ends, a pawl on said ratchet, and an abutment positioned adjacent to the surface, the abutment being moved into engagement with the second end of the lever near said end of said movement of said supporting member, continued movement of said supporting member toward said end pivoting the lever and imparting movement to said pawl which is communicated through the ratchet to the reel.
Claim 11
Dependent Claim
22 words
A device according to claim 6 wherein the supporting member is provided with means for moving the supporting member across the surface.
Claim 12
Dependent Claim
46 words
A device according to claim 8 wherein the moving means comprises a guide mounting the supporting member for slideable movement, a pivotally mounted lever engaging the supporting member, and means for pivoting the lever, said pivoting of said lever imparting slide movement to the supporting member.
Claim 13
Dependent Claim
45 words
A device according to claim 9 wherein the pivoting means comprises a pin received within a longitudinal slot formed in the lever, and means connected to the pin for moving the pin about a circular path, said circular movement imparting pivotal movement to said lever.
Claim 14
Dependent Claim
25 words
A device according to claim 9 wherein the supporting member is provided with an outwardly extending pin received within a slot formed in the lever.
Claim 15
Dependent Claim
18 words
A device according to claim 1 wherein the supporting member is supported apart from the electrically conductive surface.
References Cited (Backward Citations)
GB433172A
Cited
US2360434A
Cited
US2681571A
Cited
US2768370A
Cited
US2759175A
Cited
GB822566A
Cited
US3253315A
Cited
US3332279A
Cited
US3721970A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |