Patent US4356705A successfully refreshed from Google Patents.
Patent US2385012A successfully refreshed from Google Patents.
US3710110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ionization fire alarm device with shielding for its electrical circuitry
Assignee: Cerberus AG
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Filing: 1970-05-14
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Granted: 1973-01-09
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Expires: 1990-05-14
Abstract
Abstract An ionization fire alarm which is of the type comprising a measuring or detecting ionization chamber electrically connected in series with a resistance element, preferably constructed as a reference ionization chamber, and wherein an electrode of the measuring ionization chamber is in the form of a plate arranged to shield the interior of the measuring ionization chamber from an electrical circuit to which such electrode is connected. According to further important aspects of the invention, the aforementioned reference ionization chamber also has an electrode in the form of a plate likewise arranged to shield the interior of such reference ionization chamber from the electrical circuit. The electrical circuit is advantageously positioned between the two plate electrodes.
Inventors
- 👤 M Kuhn
- 👤 T Lampart
- 👤 A Scheidweiler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:02
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/10; G08B17/11; G08B17/113
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
120 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with both of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said measuring ionization chamber from said electric circuit with which said electrode is connected, said reference ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said reference ionization chamber from said electric circuit, said electric circuit comprising substantially all of its essential elements being positioned between said two plate electrodes.
Claim 2
Dependent Claim
120 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with both of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said measuring ionization chamber from said electric circuit with which said electrode is connected, said reference ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said reference ionization chamber from said electric circuit, said electric circuit comprising substantially all of its essential elements being positioned between said two plate electrodes.
Claim 3
Dependent Claim
22 words
An ionization fire alarm device as defined in claim 1, wherein said electric circuit is encapsulated in a block of insulating material.
Claim 4
Dependent Claim
22 words
An ionization fire alarm device as defined in claim 1, wherein each said plate electrode substantially possesses the form of a disc.
Claim 5
Dependent Claim
25 words
An ionization fire alarm device as defiNed in claim 1, wherein the spacing of said plate electrodes from one another does not exceed 20 mm.
Claim 6
Dependent Claim
42 words
An ionization fire alarm device as defined in claim 1, wherein said reference ionization chamber includes a second electrode forming a wall of such chamber, and wherein the distance between said electrodes of said reference ionization chamber does not exceed 20 mm.
Claim 7
Dependent Claim
25 words
An ionization fire alarm device as defined in claim 5, further including means for varying the spacing between said electrodes of said reference ionization chamber.
Claim 8
Dependent Claim
51 words
An ionization fire alarm device as defined in claim 1, wherein said reference ionization chamber includes a second electrode, at least one of both electrodes of said reference ionization chamber being constructed as a movable membrane for the purpose of adjusting the spacing between said electrodes of said reference ionization chamber.
Claim 9
Dependent Claim
29 words
An ionization fire alarm device as defined in claim 7, further including means for displacing said movable membrane in order to vary the characteristics of said reference ionization chamber.
Claim 10
Dependent Claim
155 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with both of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said measuring ionization chamber from said electric circuit with which said electrode is connected, said reference ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said reference ionization chamber from said electric circuit, said electric circuit being positioned between said two plate electrodes, an insulating member supporting said plate electrode of said measuring ionization chamber, said insulating member possessing a surface formed to provide an extended leakage path between said plate electrode of said measuring ionization chamber and another metallic member at a different potential.
Claim 11
Dependent Claim
155 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with both of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said measuring ionization chamber from said electric circuit with which said electrode is connected, said reference ionization chamber incorporating an electrode in the form of a plate positioned to shield the interior of said reference ionization chamber from said electric circuit, said electric circuit being positioned between said two plate electrodes, an insulating member supporting said plate electrode of said measuring ionization chamber, said insulating member possessing a surface formed to provide an extended leakage path between said plate electrode of said measuring ionization chamber and another metallic member at a different potential.
Claim 12
Dependent Claim
104 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with the interconnected electrodes positioned within each of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate, and an insulating member supporting said plate electrode of said measuring ionization chamber, said insulating member possessing a surface formed to provide an extended leakage path between said plate electrode of said measuring ionization chamber and another metallic member at a different potential.
Claim 13
Dependent Claim
104 words
An ionization fire alarm device comprising a measuring ionization chamber, a resistance element defining a reference ionization chamber, said measuring ionization chamber being electrically connected in series with said reference ionization chamber, an electric circuit electrically coupled with the interconnected electrodes positioned within each of said ionization chambers, said measuring ionization chamber incorporating an electrode in the form of a plate, and an insulating member supporting said plate electrode of said measuring ionization chamber, said insulating member possessing a surface formed to provide an extended leakage path between said plate electrode of said measuring ionization chamber and another metallic member at a different potential.
References Cited (Backward Citations)
US3231778A
Cited
US3448261A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |