EP0306269A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Double-enveloped electric lamp
Assignee: Osram Sylvania Inc
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Filing: 1988-08-30
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Granted: —
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Expires: 2008-08-30
Abstract
Abstract A double-enveloped lamp (10) has a shield (28) surrounding a light-source capsule (20) within a thick-walled outer envelope (12) so that the lamp (10) may be safely operated without necessity of a protective fixture. In the rare event of a burst of the light-source capsule (20), the shield (28) absorbs and dissipates a portion of the burst energy sufficient to permit the thick-walled outer envelope (12) to remain intact and contain shards and other internal parts within the lamp (10). In alternate embodiments, the shield (28) may be reinforced, such as with a wire mesh (50), or the outer envelope (12) may be reinforced, such as with a polymer coating, or both. A thin-walled capsule (20) may be employed in combination with a shield (28) and thick outer envelope (12). A lamp (10) in accordance with the invention provides the unexpected benefits of improved luminous efficacy and better color rendering characteristics, since the presence of an optimally positioned shield (28) causes the operation of the light-source capsule (20) to be more nearly isothermal.
Inventors
- 👤 William M Keeffe
- 👤 Robert J Karlotski
- 👤 Joseph S Kulik
- 👤 Simone P Bazin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 09:30
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/045; H01J61/30; H01J61/34
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
134 words
A double-enveloped electric lamp comprising; (a) a light-transmissive outer envelope enclosing an interior, said outer envelope having a minimum wall thickness greater than one millimeter; (b) a light-source capsule mounted within said outer envelope, said light-source capsule having an operating wattage, said light-source capsule being subject to burst on rare occasions; (c) means for shielding said outer envelope by absorbing and dissipating a portion of the energy of a burst of said light-source capsule, said shielding means including a light-transmissive shield mounted within said outer envelope, said shield substantially surrounding said light-source capsule; and (d) means within said lamp for providing electrical power from an external source to said light-source capsule and for mechanically completing said lamp; whereby said outer envelope will remain intact in the event of a burst of said light-source capsule.
Claim 2
Dependent Claim
134 words
A double-enveloped electric lamp comprising; (a) a light-transmissive outer envelope enclosing an interior, said outer envelope having a minimum wall thickness greater than one millimeter; (b) a light-source capsule mounted within said outer envelope, said light-source capsule having an operating wattage, said light-source capsule being subject to burst on rare occasions; (c) means for shielding said outer envelope by absorbing and dissipating a portion of the energy of a burst of said light-source capsule, said shielding means including a light-transmissive shield mounted within said outer envelope, said shield substantially surrounding said light-source capsule; and (d) means within said lamp for providing electrical power from an external source to said light-source capsule and for mechanically completing said lamp; whereby said outer envelope will remain intact in the event of a burst of said light-source capsule.
Claim 3
Dependent Claim
48 words
A lamp as claimed in Claim 1, wherein said lamp includes means for reinforcing said shield such that the ability of said shield to remain intact after a burst of said light-source capsule is improved in comparison to the ability of said shield unaided by said reinforcing means.
Claim 4
Dependent Claim
58 words
A lamp as claimed in Claim 1 or 2, wherein said lamp includes means for reinforcing said outer envelope such that said outer envelope has the ability to contain a burst of a light-source capsule having a higher operating wattage than a light-source capsule capable of being contained by said outer envelope unaided by said outer-envelope reinforcing means.
Claim 5
Dependent Claim
33 words
A lamp as claimed in any preceding Claim, wherein said light-source capsule includes a body and at least one end, and said capsule body has a maximum wall thickness less than one millimeter.
Claim 6
Dependent Claim
50 words
A lamp as claimed in any preceding claim wherein said shield comprises a mesh surrounding said light-source capsule, or comprises a surface surrounding said light-source capsule, said surface being subject to being shattered by a burst of said light-source capsule and preferably having a maximum wall thickness of two millimeters.
Claim 7
Dependent Claim
44 words
A lamp as claimed in Claim 1, wherein said outer envelope has a minimum wall thickness sufficient to insure that said outer envelope will contain all shards of said light-source capsule and said shield in the event of a burst of said light-source capsule.
Claim 8
Dependent Claim
89 words
A lamp as claimed in Claim 1, wherein said shield is heat-reflecting, and the luminous efficacy, color-rendering ability, and life of said lamp are substantially improved in comparison with the same lamp without the presence of said shield, said light-source capsule preferably includes a central body having a maximum cross-sectional outer radius of approximately 11 millimeters, and said shield preferably includes a central body substantially surrounding said central body of said light-source capsule, said central body of said shield having a maximum cross-sectional inner radius of approximately 17.5 millimeters.
Claim 9
Dependent Claim
22 words
A lamp as claimed in Claim 1, wherein said shield comprises a right circular cylinder open at both ends of said cylinder.
Claim 10
Dependent Claim
28 words
A lamp as claimed in Claim 8, wherein said light-source capsule is single-ended, and said cylindrical shield laterally surrounds said body and said end of said light-source capsule.
Claim 11
Dependent Claim
30 words
A lamp as claimed in Claim 8, wherein said light-source capsule is double-ended, and said cylindrical shield laterally surrounds said body and both of said ends of said light-source capsule.
Claim 12
Dependent Claim
24 words
A lamp as claimed in Claim 9 or 10, wherein said cylindrical shield has a dome on at least one end of said shield.
Claim 13
Dependent Claim
52 words
A lamp as claimed in Claim 1, wherein said outer envelope is hermetically sealed, and a vacuum is contained within said outer envelope, or the atmosphere within said outer envelope includes nitrogen and the pressure within said outer envelope is preferably approximately one atmosphere when said lamp is in steady state operation.
Claim 14
Dependent Claim
16 words
A lamp as claimed in Claim 1, wherein said light-source capsule is a tungsten-halogen incandescent capsule.
Claim 15
Dependent Claim
22 words
A lamp as claimed in Claim 1, wherein said light-source capsule is an arc discharge tube, preferably a metal-halide arc discharge tube.
Claim 16
Dependent Claim
25 words
A lamp as claimed in Claim 13 or 14, wherein said lamp has an operational wattage of approximately one hundred and seventy-five watts or greater.
Claim 17
Dependent Claim
42 words
A lamp as claimed in Claim 5, wherein said shield has a wall thickness sufficient to insure that said outer envelope will contain all shards of said light-source capsule and said shield in the event of a burst of said light-source capsule.
Claim 18
Dependent Claim
18 words
A lamp as claimed in Claim 1, wherein said shield is formed from quartz glass or from vycor.
Claim 19
Dependent Claim
96 words
A lamp as claimed in Claim 1, wherein said light-source capsule includes a central body having a maximum wall thickness, x; said shield includes a central body substantially surrounding said central body of said light-source capsule, said central body of said shield having a minimum wall thickness, y; said outer envelope includes a body and a neck, said body of said outer envelope substantially enclosing said light-source capsule and said shield, said body of said outer envelope having a minimum wall thickness, z; and the ratio y/x falls within the range of approximately two to one.
Claim 20
Dependent Claim
19 words
A lamp as described in Claim 1, wherein said outer envelope and/or said shield is formed from tempered glass.
Claim 21
Dependent Claim
77 words
A lamp as claimed in Claim 1, wherein said light-source capsule includes a central body having a maximum cross-sectional outer radius, u; said shield is substantially a right circular cylinder with inner radius, v; said outer envelope includes a bulbous central portion laterally surrounding said light-source capsule and said shield, said bulbous portion having a maximum inner radius, w; and the ratio v/u falls within the range of approximately .5 to .7 and is preferably approximately .63.
Claim 22
Dependent Claim
20 words
A lamp as claimed in Claim 1, wherein said lamp is a reflector-type lamp, preferably including a parabolic aluminized reflector.
Claim 23
Dependent Claim
41 words
A lamp as claimed in Claim 1, wherein said lamp is single-ended and said envelope preferably has a mogul type base mounted on said end of said lamp or has a standard Edison-type base mounted on said end of said lamp.
Claim 24
Dependent Claim
54 words
A lamp as claimed in Claim 1, wherein said lamp has a central axis, and said lamp is designed to be operated with said axis substantially vertical, and preferably said lamp is single-ended having a base mounted on said end of said lamp, said lamp being designed to be operated in the base-up position.
Claim 25
Dependent Claim
43 words
A lamp as claimed in Claim 1, wherein said light-source capsule includes a central body and at least one end, and said capsule has a heat-reflecting coating disposed on at least one end of said capsule, said heat-reflecting coating preferably comprising zirconium oxide.
Claim 26
Dependent Claim
56 words
A lamp as described in Claim 2, wherein said shield reinforcing means is mounted on said shield which preferably includes an exterior surface substantially facing said outer envelope, and said shield reinforcing means includes a wire mesh mounted on said outside surface of said shield, said wire mesh preferably being formed from loosely-woven stainless steel wire.
Claim 27
Dependent Claim
58 words
A lamp as claimed in Claim 3, wherein said outer envelope includes an inside surface substantially facing said light-source capsule and said shield and an outside surface substantially facing the exterior of said lamp, and said outer-envelope reinforcing means includes a coating disposed on one of said surfaces of said outer envelope, said coating preferably including a polymer.
Claim 28
Dependent Claim
31 words
A lamp as claimed in Claim 1, wherein said lamp includes an electrically conductive frame within said outer envelope, and said light-source capsule and said shield are mounted on said frame.
Claim 29
Dependent Claim
39 words
A lamp as claimed in Claim 1, wherein said lamp includes an electrically conductive frame within said outer envelope, said frame being electrically isolated from the electrical circuit of said lamp and preferably being formed from stiff metal wire.
References Cited (Backward Citations)
No citation records indexed.
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