EP0074720A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Discharge lamps
Assignee: EMI Group Ltd
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Filing: 1982-08-13
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Granted: —
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Expires: 2002-08-13
Abstract
Abstract High pressure discharge lamps have discharge tubes (1) of ceramic material having end caps (4) into which electrodes (8) are mounted on fixed shanks (7). The invention provides a preferred construction for mounting on electrode shank (7) or an external conducting member (11) in a cermet end cap (4). A metal coil (10 or 11) is fixed in a respective opening in the end cap and supports the respective shank or conductor therein. Preferably the cermet is pressed into the desired shape with an aperture in it. The coil is inserted into the aperture so that after sintering the coil is fixed into the sintered cermet.
Inventors
- 👤 James Richard Coaton
- 👤 Douglas Hussley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:26
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/36; H01J61/82; H01J61/825
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
56 words
An end closure cap for a high pressure discharge lamp, the cap being made of a conductive cermet and having, fixed in a respective opening therein, at least one metal coil to receive and support a refractory metal rod forming part of an electrode assembly or a metal rod forming part of an external connection thereto.
Claim 2
Dependent Claim
56 words
An end closure cap for a high pressure discharge lamp, the cap being made of a conductive cermet and having, fixed in a respective opening therein, at least one metal coil to receive and support a refractory metal rod forming part of an electrode assembly or a metal rod forming part of an external connection thereto.
Claim 3
Dependent Claim
64 words
A cap according to claim 1 of substantially circular cross-section comprising two portions of different diameter, the portion of smaller diameter being adapted to be inserted into a discharge tube wherein said coil is fixed in an opening disposed substantially axially in the end face of the smaller diameter portion to receive and support a refractory metal rod forming part of an electrode assembly.
Claim 4
Dependent Claim
41 words
A cap according to claim 2 further including a second metal coil fixed in an opening in the end face of the larger diameter portion to receive and support a metal rod forming part of an electrical connection to the electrode.
Claim 5
Dependent Claim
19 words
A tap according to any preceding claim in which the at least one coil is made of doped molybdenum.
Claim 6
Dependent Claim
22 words
A cap according to any of claims 1 - 5 in which the at least one coil is made of thoriated tungsten.
Claim 7
Dependent Claim
22 words
A cap according to any of claims 1 - 5 in which the at least one coil is made of AKS tungsten.
Claim 8
Dependent Claim
33 words
A cap according to any preceding claim having fixed in and supported by said coil a refractory metal electrode shank, said shank having mounted thereon an electrode coil impregnated with electron emissive material.
Claim 9
Dependent Claim
78 words
A discharge tube assembly for a high pressure discharge lamp, comprising a polycrystalline alumina discharge tube having sealed into one or both ends in a gas tight manner an end closure cap according to any of claims 1 - 9 and, fixed in and supported by the metal coil, a refractory metal electrode shank having mounted thereon an electrode coil impregnated with electron emissive material, the assembly being filled with a filling including an alkali metal and mercury.
Claim 10
Dependent Claim
14 words
A high pressure discharge lamp including a discharge tube assembly according to claim 8.
Claim 11
Independent Claim
70 words
A method of constructing an end closure cap for a high pressure discharge lamp, the method comprising: pressing a conductive cermet powder,, into a desired shape, having an aperture in at least one end thereof, to approximately 50% of the desired final density; inserting a metal coil into said aperture; and sintering the cermet with the coil inserted therein to attain its final density and to fix the coil therein.
Claim 12
Independent Claim
70 words
A method of constructing an end closure cap for a high pressure discharge lamp, the method comprising: pressing a conductive cermet powder,, into a desired shape, having an aperture in at least one end thereof, to approximately 50% of the desired final density; inserting a metal coil into said aperture; and sintering the cermet with the coil inserted therein to attain its final density and to fix the coil therein.
Claim 13
Independent Claim
42 words
A method of assembling a discharge tube assembly for high pressure discharge lamp the method including mounting and supporting an electrode shank in a conductive cermet end cap by means of a coil support prefixed into an aperture in the end cap.
Claim 14
Independent Claim
42 words
A method of assembling a discharge tube assembly for high pressure discharge lamp the method including mounting and supporting an electrode shank in a conductive cermet end cap by means of a coil support prefixed into an aperture in the end cap.
References Cited (Backward Citations)
No citation records indexed.
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