Patent-treuhand-gesellschaft F. Elektrische Gluehlampen Mbh

Ngk Insulators, Inc.

Osram Sylvania Inc.

Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Patent-treuhand-gesellschaft Fuer Elektrische Gluehlampen Mbh

Osram Ag

Patent-truehand-gesellschaft Fuer Electriche Gluelampen Mbh

Stefan Juengst

Roland Huettinger

Juergen Heider

Stefan Kotter

Osamu Asano

Hartmuth Bastian

George C Wei

Steffen Walter

Koichiro Maekawa

Peter Wahrendorff

John H Selverian

Khanh Pham Gia

Dieter Hofmann

Wolfgang Pabst

Kouichiro Maekawa

Dieter Brunner

Jens Clark

Rodrique G Thibodeau

John Selverian

A high pressure discharge lamp may include a ceramic discharge vessel and a longitudinal axis, wherein at least one electrode is led out of the discharge vessel by means of a metal-containing feed-through, wherein the feed-through is connected to one end of the discharge vessel by way of a ceramic-containing adjustment part, wherein the adjustment part is tubular and consists of individual layers with different compositions, at least two materials A and B forming a plurality of layers of the adjustment part, these materials being chosen such that their coefficient of thermal expansion is between that of the feed-through and that of the end of the discharge vessel or at most is just outside, the layer thickness of each layer being so low that no shearing forces can occur, and the layer thickness of each layer of the same material being different.

High pressure discharge lamp

A high-pressure discharge lamp may include a ceramic discharge vessel and a longitudinal axis, with electrodes respectively being led out from the discharge vessel by means of a feed-through via capillaries, wherein a tubular cermet part, which consists of individual layers of different composition layered axially in succession, is fitted on the capillary, each layer containing Mo and AlO, the proportion of Mo in the first layer facing toward the capillary being from 3 to 15 vol. % and in the last layer being from 85 to 97 vol. %, and a molybdenum cover cap, the cover cap being welded to the feed-through and the cover cap being connected to the cermet part by means of solder containing metal, and the connection between the capillary and the cermet part being established by means of high-melting glass solder or sinter-active AlOpowder.

To close off tubular ends (,) of a metal-halide discharge vessel, a plug (,) having at least four, and preferably six or more, axially arranged layers or strata (,) of a cermet, in which the metal content of the cermet of the respective layers or strata increases from the layer or stratum closest to the discharge space of the vessel to the outside. The innermost layer or stratum is directly sintered to the ceramic discharge vessel, typically of aluminum oxide, whereas the outermost layer or stratum has a metal content of such an extent that it can be welded, and is welded, to a metallic or cermet lead-through or feed-through (,) leading through a central opening in the respective layers or strata of the plug. The outermost layer of the plug, preferably, has at least 50%, by volume, of metal, preferably of the same material as that of the lead-through in the cermet, and may even be made entirely of metal, to ensure a tight, easily made weld connection. The weld can be made, for example, by laser welding.

Metal halide lamp with aluminum gradated stacked plugs

The discharge vessel has two ends (6), which are closed off by ceramic pl which each contain an elongate capillary tube (12), an electrically conductive lead-through (9, 10) comprising two parts (13, 14) being guided in a vacuum-tight manner through this plug capillary tube (12). The inner part (14) is a pin made of a halide-resistant metal (tungsten), the diameter of which is at most 0.4 mm and which is surrounded by a tubular casing (20, 21) made of ceramic material which consists of a concentric aluminum oxide tube (sleeve), the outer part (13), over its entire length, and the inner part (14), at least over a length of 1 mm from the beginning of the sleeve (20, 21), being sealed off by means of soldering glass (18).

Metal-halide lamp with specific lead through structure

This invention involves a new type of feedthrough-plug member for metal halide HID lamp using PCA envelopes. The construction of the lamp housing consists of a PCA envelope and specially designed radially graded alumina-metal cermet multi-layers to eliminate cracking in cermet or PCA due to thermal stresses arising from thermal expansion mismatch. The fills are metal halides such as Na-Sc-I, rare earth halides, Hg, Sn, and inert gases. The PCA vessel and directly sealed cermetfeedthrough assemblies allow the metal halide lamps to operate at high wall temperatures with better lumen output, color temperature, and CRI.

Lamp with radially graded cermet feedthrough assembly

This invention involves a new type of feedthrough-plug member for metal halide HID lamp using PCA envelopes. The construction of the lamp housing consists of a PCA envelope and specially designed axially graded alumina-metal cermet multi-layers to eliminate cracking in cermet or PCA due to thermal stresses arising from thermal expansion mismatch. The fills are metal halides such as Na--Sc--I, rare earth halides, Hg, Sn, and inert gases. The PCA vessel and directly sealed cermet-feedthrough assemblies allow the metal halide lamps to operate at high wall temperatures with better lumen output, color temperature, and CRI.

Ceramic envelope device, lamp with such a device, and method of

A ceramic discharge vessel (8) for a high-pressure discharge lamp has a pin-like feedthrough (10) inserted in a plug (11) made from a composite material. The feedthrough (10) has been sintered directly into the plug (11) and is additionally sealed by covering the area, surrounding the feedthrough, of the plug's surface facing away from the discharge volume with a ceramic sealing material (7a).

High-pressure discharge lamp, method of its manufacture, and sealing

Ceramic discharge vessel for a high-pressure discharge lamp, having a

A high pressure discharge lamp having an extended life includes a discharge vessel 8, and a feedthrough 10 extending through a plug 11. A directly sintered connection is formed between the feedthrough 10 and the plug 11 wherein sealing material 7 is provided covering the area surrounding the feedthrough on the outer surface of the plug 11. The plug 11 is formed of a composite material whose thermal expansion coefficient lies between that of the ceramic vessel and of the metal feedthrough.

High pressure discharge lamp including directly sintered feedthrough

A vacuum-tight seal, particularly for an arc tube or discharge vessel for a metal halide or sodium high-pressure discharge lamp, is made by forming the arc tube of transparent ceramic, typically Al.sub.2 O.sub.3, having two open ends, into which connecting plugs (3), with central openings, are sealed. Open metal tubes (4) fitting into the openings of the plugs (3) are then vacuum-tightly sintered therein. An electrode system (5, 10, 10'), forming a subassembly with a current supply lead or lead-through (6, 11, 14, 15, 20, 24) is provided, having an outer diameter fitting into the metal tube. After mounting one of the electrode systems and lead-through into the metal tube (4), and welding the lead-through to the metal tube, the vessel can be evacuated through the still open tube (4) at the other end, supplied with suitable fill substances and an ignition gas, such as argon or xenon, and the second electrode system then introduced, and welded, for example by a laser, to the outer end of the other metal tube (4). The arrangement permits use of molybdenum tubes, molybdenum lead-throughs, in Al.sub.2 O.sub.3 ceramic, in spite of different thermal coefficients of expansion. Preferably, the metal tube extends beyond the end face of the vessel and/or sealing plug (3), to permit free access during the welding step and reduce heat transfer into the interior of the arc tube or discharge vessel (1).

Method of making a vacuum-tight seal between a ceramic and a metal part,

To provide an effective seal for a metal-halide discharge lamp having a ceramic discharge vessel (4), the seal is formed in multiple parts, in which a first part, adjacent the interior or discharge side of the vessel, includes a melt component (14a) which is highly resistant to attack by metal halides within the fill of the lamp. It may contain only 0-12%, by weight, of SiO.sub.2 and has a high melting point, in the order of between 1500.degree.-1700.degree. C. The melt-in region remote from the discharge side is melt-sealed by a vitreous composition (14b), devoid of pores, voids, bubbles, fissures or cracks, to form an effective, vacuum-tight seal, and protected from attack by the metal halides by the mechanically less stable seal in the first zone. The second composition has a much lower melting point, for example in the order of between 1200.degree.-1400.degree. C., and has 20-40% SiO.sub.2. Preferably, and for ease of manufacture, the capillary gap in which the melt seal is formed decreases in dimension towards the discharge side, so that an effective capillary seal can be formed at the higher melting point temperature before the second, lower melting point temperature seal is made.

Metal-halide discharge lamp with ceramic discharge vessel, and method of

Method for producing a metal-halide discharge lamp with a ceramic

To provide a sealed through arrangement for electrical leads through a ceramic end plug, suitable for discharge lamps of between about 50 to 250 W power rating, the lead-through (9) is made of a material having a thermal coefficient of expansion which is substantially less than that of a ceramic sealing plug (10), for example of tungsten, molybdenum or rhenium, but so small that the individual, actual expansion of the ceramic material will not cause separation from the metal, and/or a glass melt, ceramic melt or sintar connection therewith. The electrical connection is formed by at least two, and preferably more than two, thin wires or pins (23) having a diameter, each, of up to only about 0.25 mm, and preferably less. Each of the wires, then, will carry currents in the tenths ampere ranges, sufficient for operation of the lamp, and passed through melt-sealed capillary openings in the ceramic sealing plug (10).

High-pressure discharge lamp with ceramic discharge vessel and ceramic

To provide a tight seal between an essentially solid niobium or tantalum necting pin or rod (10) passing through an opening (7, 28) in an end plug (11) closing off a high-pressure discharge lamp discharge vessel (8), the pin or rod is formed with two axial portions, one of which has externally projecting continuous rings (17), preferably two or three, or an externally projecting thread (26). The rings or thread are press-fitted into the end portion of the bore in the plug, which deforms the edge (20) of the rim, ridge or thread, or shears off the edge portion, ensuring a tight preliminary fit in the bore; sealing glass, which is then melted to fill a capillary space between the pin or rod and the plug, is protected by the preliminary seal against corrosion or attack from the fill within the discharge lamp; if the projection is in form of a thread, glass can penetrate within the threads to further seal and retain the pin or rod. Diffusion-welding of the threads or ridges to the walls of the plug can also be used.

High-pressure electric discharge lamp with tight lead-through pin

To protect a niobium tube (9) forming a current supply lead through a thrh-opening (14) in an end plug (10) in a ceramic discharge vessel against attack by halides or condensed sodium, the through-opening is formed in two portions, of different diameters. The outer portion (16), remote from the discharge vessel, has a diameter which is matched to the diameter of the tube (9), leaving only a capillary between the plug opening and the tube; the second, inner portion (17) is narrower than the first one, that is, outer portion, and surrounds the shaft of the electrode by a sufficient distance to permit expansion of the electrode, typically of tungsten, under operating conditions, without cracking the plug by forced engagement with the wall of the inner portion (17) of the aperture. A sealing glass, melt-sealed into the capillary of the outer portion, seals the niobium tube. Preferably, the niobium tube terminates inwardly in a dome-shaped end (20) seated in a similarly shaped cavity forming the transition between the two diameters of the through-opening, and also providing a capillary space for ingress of molten sealing glass. The inner diameter of the outer portion (16) of the through-opening differs, preferably, by at most about 0.05 mm from the outside diameter of the tube (9), whereas the diameter of the inner portion (17) of the through-opening (14) differs by at least 0.5 mm from the diameter of the electrode shaft.

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Zorneding, Germany

Stefan Juengst