US3898503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual cathode structure
Assignee: Duro Test Corp
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Filing: 1970-12-16
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Granted: 1975-08-05
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Expires: 1990-12-16
Abstract
Abstract A dual cathode structure for a fluorescent lamp comprising a pair of electron emissive cathodes which are connected with a common junction and mounted to have an included angle therebetween. An anode flag is connected to the common junction to collect electrons when the filaments are operating in the anode half cycle. The collected electrons pass through one or both of the cathodes to diffuse the hot spot on the electrode. The lamp operates with reduced wattage with no decrease of light output.
Inventors
- 👤 Joel Shurgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:51
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/06; H01J61/067; H01J61/0672
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
334 words
A fluorescent lamp of the type in which the cathodes receive current from a source of alternating current electrical voltage external to the lamp which supplies both heating current and operating voltage comprising a sealed envelope having a phosphor coating on the internal wall thereof and having a fill gas and an ionizable medium therein, a cathode structure means at each end of the envelope comprising an electron emissive cathode means, first and second electrically conductive leads connected to spaced points on said cathode means and extending outside of the envelope to electrically connect the cathode means to the voltage source so that alternating current from the source will flow through the portion of the cathode means electrically connected between said leads to provide heating current to the cathode during the entire time that the lamp is operating and alternately make the structure emit electrons and attract electrons during the negative and positive half cycles of the operating voltage respectively to produce an arc streaM discharge, and electrically conductive probe means for at least one of said cathode structure means having one end electrically connected only to an intermediate point of its respective electron emissive cathode means between said spaced points and the other end positioned within the envelope to extend into the path of the arc stream discharge to collect positive ions when the said one electron emissive cathode is emitting electrons and to collect electrons when said one electron emissive cathode is attracting electrons, said positive ions and said electrons collected by said other end of said probe means being alternately conducted to said one end of said probe means and then to a portion of the electron emissive cathode means of said one cathode structure means, the collected ions causing the heating current flowing through the electron emissive cathode means of said one cathode structure means causing a redistribution of the current to neutralize the ions, and the collected electrons also flowing through a portion of the electron emissive cathode means.
Claim 2
Dependent Claim
334 words
A fluorescent lamp of the type in which the cathodes receive current from a source of alternating current electrical voltage external to the lamp which supplies both heating current and operating voltage comprising a sealed envelope having a phosphor coating on the internal wall thereof and having a fill gas and an ionizable medium therein, a cathode structure means at each end of the envelope comprising an electron emissive cathode means, first and second electrically conductive leads connected to spaced points on said cathode means and extending outside of the envelope to electrically connect the cathode means to the voltage source so that alternating current from the source will flow through the portion of the cathode means electrically connected between said leads to provide heating current to the cathode during the entire time that the lamp is operating and alternately make the structure emit electrons and attract electrons during the negative and positive half cycles of the operating voltage respectively to produce an arc streaM discharge, and electrically conductive probe means for at least one of said cathode structure means having one end electrically connected only to an intermediate point of its respective electron emissive cathode means between said spaced points and the other end positioned within the envelope to extend into the path of the arc stream discharge to collect positive ions when the said one electron emissive cathode is emitting electrons and to collect electrons when said one electron emissive cathode is attracting electrons, said positive ions and said electrons collected by said other end of said probe means being alternately conducted to said one end of said probe means and then to a portion of the electron emissive cathode means of said one cathode structure means, the collected ions causing the heating current flowing through the electron emissive cathode means of said one cathode structure means causing a redistribution of the current to neutralize the ions, and the collected electrons also flowing through a portion of the electron emissive cathode means.
Claim 3
Dependent Claim
30 words
A fluorescent lamp as in claim 1 wherein said cathode structure including said probe means has the probe means connected substantially at the mid-point of the electron emissive cathode means.
Claim 4
Dependent Claim
49 words
A fluorescent lamp as in claim 2 wherein said envelope is elongated and has a longitudinal axis, means mounting said electron emissive cathode means to be substantially transverse to said longitudinal axis, said probe means also having a substantial portion thereof which is substantially transverse to said longitudinal axis.
Claim 5
Dependent Claim
49 words
A fluorescent lamp as in claim 1 wherein said envelope is elongated and has a longitudinal axis, means mounting said electron emissive cathode means to be substantially transverse to said longitudinal axis, said probe means also having a substantial portion thereof which is substantially transverse to said longitudinal axis.
Claim 6
Dependent Claim
40 words
The fluorescent lamp of claim 4 wherein said electron emissive cathode means is mounted to have two portions with an included angle of not greater than 90* therebetween and said probe means is located at the apex of said angle.
Claim 7
Dependent Claim
106 words
The fluorescent lamp of claim 1 further comprising insulated mounting means for said cathode structure means sealed at each end of said envelope, said insulated mounting means for said cathode structure means having said probe means including a base of insulated material and first, second and third electrically conductive support means affixed to said base, means electrically connecting said electron emissive cathode means between said first and second and said second and third support means to form two portions, said first and second leads being electrically connected to said first and third support means, and means electrically connecting said probe means to said second support means.
Claim 8
Dependent Claim
41 words
The fluorescent lamp of claim 6 wherein said conductive probe means is electrically connected to said second electrically conductive support means and includes a portion which is located between the electron emissive cathode means at the respective ends of the envelope.
Claim 9
Dependent Claim
40 words
The fluorescent lamp of claim 1 wherein said probe means has the portion thereof for collecting the positive ions and the electrons located between the electron emissive cathode means of the cathode structures at the respective ends of the envelope.
Claim 10
Dependent Claim
22 words
A fluorescent lamp as in claim 1 wherein the cathode structure at each end of the envelope includes a conductive probe means.
Claim 11
Dependent Claim
54 words
A fluorescent lamp as in claim 9 wherein said envelope is elongated and has a longitudinal axis, means for mounting each said electron emissive cathode means to be generally transverse of said longitudinal axis and said probe means being formed to have a substantial portion thereof to be generally transverse to said longitudinal axis.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |