US4072467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combustible gas detectors
Assignee: Teledyne UK Ltd
•
Filing: 1976-10-15
•
Granted: 1978-02-07
•
Expires: 1996-10-15
Abstract
Abstract A gas detector consists of a heatable wire filament which exhibits a change in resistance when its temperature rises due to the oxidization of a combustible gas pouring over it. The filament is embedded in a pellet consisting of a homogeneous mixture of an oxidization catalyst material and a substantially non-catalytic carrier material. A layer of the oxidization catalyst material is produced on the outside of the pellet.
Inventors
- 👤 Eric Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:02
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A gas detector of the kind in which a heatable wire filament exhibits a change in resistance occasioned by the change in its temperature which occurs due to the oxidisation of a combustible gas passing over it and wherein said heatable wire filament is embedded in a pellet consisting of a homogeneous mixture of an oxidisation catalyst material and a substantially non catalytic carrier material and a layer of oxidisation catalyst material is provided on the outside of said homogeneous pellet.
Claim 2
Dependent Claim
81 words
A gas detector of the kind in which a heatable wire filament exhibits a change in resistance occasioned by the change in its temperature which occurs due to the oxidisation of a combustible gas passing over it and wherein said heatable wire filament is embedded in a pellet consisting of a homogeneous mixture of an oxidisation catalyst material and a substantially non catalytic carrier material and a layer of oxidisation catalyst material is provided on the outside of said homogeneous pellet.
Claim 3
Dependent Claim
16 words
A gas detector as claimed in claim 1 and wherein said layer completely surrounds said pellet.
Claim 4
Dependent Claim
30 words
A gas detector as claimed in claim 1 and wherein said catalyst material of said homogeneous mixture forming said pellet and said catalyst material of said layer are both palladium.
Claim 5
Dependent Claim
30 words
A gas detector as claimed in claim 1 and wherein said catalyst material of said homogeneous mixture forming said pellet and said catalyst material of said layer are both platinum.
Claim 6
Dependent Claim
32 words
A gas detector as claimed in claim 1 and wherein said catalyst material of said homogeneous mixture forming said pellet and said catalyst material of said layer are both palladium and platinum.
Claim 7
Dependent Claim
15 words
A gas detector as claim in claim 1 and wherein said carrier material is alumina.
Claim 8
Dependent Claim
54 words
A balanced bridge circuit arrangement including a gas detector as claimed in claim 1 and wherein a compensating element is included which consists of a wire filament embedded in a pellet consisting of a homogeneous mixture of a substantially non catalytic carrier material and a poison acting to suppress the oxidisation of combustible gases.
Claim 9
Dependent Claim
17 words
A balanced bridge circuit arrangement as claimed in claim 7 and wherein said poison is potassium hydroxide.
Claim 10
Dependent Claim
25 words
A balanced bridge circuit arrangement as claimed in claim 7 and wherein the wire filament of said detector and said compensating element is of platinum.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |