Patent Application
20120306347
The present disclosure relates generally to an ultraviolet (UV) radiation starting source, or ultraviolet enhancer (UVE), for a metal halide lamp, and, more particularly, to a UVE holder.
Metal halide arc discharge lamps may have high luminous efficacy and long life and may be employed in commercial usage. In one embodiment, a metal halide arc discharge lamp may include a quartz or fused silica arc tube that is hermetically sealed within a borosilicate glass outer envelope. The arc tube, itself hermetically sealed, may have tungsten electrodes sealed into opposite ends and may contain a fill material including mercury, metal halide additives and/or a rare gas to facilitate starting. In some cases, e.g. in high wattage lamps, the outer envelope may be filled with nitrogen or another inert gas at less than atmospheric pressure. In other cases, e.g. in low wattage lamps, the outer envelope may be evacuated.
Metal halide lamps may be configured to start upon application of a high voltage between two main electrodes or to an inductive start system. Metal halide lamps which do not contain UV enhancers may require higher voltage pulses to release avalanche initiating electrons. Initiating electrons, in this manner, are believed to be released from the electrode by field emission or by field extraction from charges in shallow traps on the wall of the arc tube. However, not all sockets into which such lamps are inserted have the capacity to carry the high voltage needed to start the lamps.
Accordingly, a starting aid, also known as an ultraviolet enhancer (UVE), may be provided in such lamps. In one embodiment, a conventional UVE may include a capsule with a sealed cavity that may contain a gas or a mixture of gases, such as mercury vapor and an inert gas (argon, helium, krypton, neon, or xenon). An electrode may extend into the cavity and may provide a voltage from one of the discharge vessel electrodes. Upon application of the starting voltage, a capacitive discharge may start in the capsule and may cause the capsule to emit UV radiation, which in turn may cause the release of photoelectrons in the lamp, which in turn may lower the voltage needed to start the lamp.
In one embodiment, a metal halide lamp may include a discharge vessel in an outer bulb. The discharge vessel may have two electrodes that receive the voltage for starting the lamp. The UVE may be located within the outer bulb and connected to one of the electrodes. The UVE may be positioned close to the other electrode to allow capacitive coupling. A gas inside the UVE may be partially ionized by the capacitive coupling and may emit UV light that aids in starting the lamp.
In some applications, it may be desirable to provide a holding means configured to hold the UVE in a particular position within the lamp. Examples of lamps utilizing such holding means may be found, for example, in EP 2151850 A2 (Ishida), U.S. Patent Pub. No. 2008/0169744 (Fortuna); U.S. Pat. No. 6,392,343 (Luijks); U.S. Pat. No. 5,248,273 (Nortrup); U.S. Pat. No. 5,122,706 (Parrot); and U.S. Pat. No. 4,818,915 (Zaslaysky).
As shown, the arc tube 106 may include first and second electrodes 112, 114. The mounting frame 110 may be non-insulated and electrically conductive and may serve as a first electrical lead, wherein a first conductive wire 116 may electrically connect a portion of the electrically conductive mounting frame 110 to the first electrode 112 of the arc tube 106. Additionally, a second conductive wire 118 may electrically connect the second electrode 114 of the arc tube 106 to a second lead 120. A portion of the mounting frame 110 and the second lead 120 pass through a lamp stem portion 122 at the base 104.
As shown, the electrically conductive mounting frame 110 and the second lead 120 are electrically connected to the base 104 external of the envelope 102 and are configured to provide energization of the lamp 100, specifically the arc tube 106. In other words, electrical energy may be coupled to the arc tube 106 through the base 104, second lead 120, mounting frame 110 and first and second conductive wires 116, 118. The arc tube 106 may contain a chemical fill or dose of materials to provide light when an arc is initiated therein, as is known.
The lamp 100 may further include a starting aid, or UVE 124, disposed within the lamp envelope 102. The UVE 124 may be electrically connected to at least the second lead 120 of the lamp 100 via a UVE electrical lead 126 extending from the UVE 124. Additionally, the lamp 100 may include a holding means 128 configured to hold the UVE 124 in a desired position within the lamp envelope 102, wherein a portion of the holding means 128 is coupled to a portion of the mounting frame 110.
In many applications, it may be desirable for the UVE to be securely and accurately placed in a certain position within a metal halide lamp. The current UVE holding means, such as the foil strip described above, have flaws in structure and/or function. For example, in regards to the foil strip described above, during manufacturing, the required close proximity of the foil strip around the glass envelope of the UVE may result in glass damage and/or breakage when the strip is wrapped around the UVE. Additionally, construction of the UVE foil strip holder may require at least two coupling points, such as the first and second welds. This may increase assembly time and manufacturing costs, as well as chance of error with regard to welding points.
Features and advantages of the claimed subject matter will be apparent from the following detailed description of embodiments consistent therewith, which description should be considered with reference to the accompanying drawings, wherein:
In general, this disclosure provides a UVE holder. The UVE holder may be configured to attach a UVE having an outer envelope to an electrical lead of a lamp and to retain the UVE within the lamp in a desired position. The UVE holder may include a plurality of turns comprising a first turn and a final turn. The first and final turns may have a substantially similar inner diameter defining a through passage shaped to conformingly receive the outer envelope of the UVE. The UVE holder may further include a first leg depending from the first turn, wherein the first leg may have a first distal portion remote from the first turn defining a first attachment region adapted for attachment to a lamp capsule electrical lead.
A UVE holder consistent with the present disclosure is configured to provide a more secure fit with less chance of UVE damage and/or breakage when compared with current UVE holders. Additionally, a UVE holder consistent with the present disclosure provides a minimum number of components and/or coupling points, resulting in less time required for assembly and less manufacturing costs.
Generally, the metal halide discharge lamp 400 may include a lamp envelope 402 and a base 404 fixed at one end of the envelope 402. As shown, the base 404 may be formed for easy connection to an electrical source. Contained within the interior space of the lamp envelope 402 is a mount assembly. The mount assembly may include a light source, lamp capsule, or arc tube 406, a shroud 408, and a mounting frame 410. In the illustrated embodiment, the arc tube 406 may be positioned within the shroud 408, wherein the arc tube 406 and shroud 408 may be supported within the envelope 402 by the mounting frame 410.
The lamp 400 may include a first electrical lead 420 extending from a portion of the base 404. Additionally, the mounting frame 410 may be non-insulated and electrically conductive and may serve as a second electrical lead, or lamp capsule lead, of the lamp 400. As shown, the arc tube 406 may include first and second electrodes 412, 414, wherein a first conductive wire 416 may electrically connect a portion of the electrically conductive mounting frame 410 to the first electrode 412 of the arc tube 406. Additionally, a second conductive wire 418 may electrically connect the second electrode 414 of the arc tube 406 to the first electrical lead 420. A portion of the mounting frame 410 and the first lead 420 pass through a lamp stem portion 422 at the base 404.
As shown, the first electrical lead 420 and the electrically conductive mounting frame 410 (second electrical lead) are electrically connected to the base 404 external of the envelope 402 and are configured to provide energization of the lamp 400, specifically the arc tube 406. In other words, electrical energy may be coupled to the arc tube 406 through the base 404, the first electrical lead 420, the mounting frame 410 (second electrical lead) and first and second conductive wires 416, 418. The arc tube 406 may contain a chemical fill or dose of materials to provide light when an arc is initiated therein, as is known.
The lamp 400 may further include a starting aid, or UVE 424, disposed within the lamp envelope 402. The UVE 424 may be electrically connected to at least the first electrical lead 420 of the lamp 400 via a UVE electrical lead 426 extending from the UVE 424. Additionally, the lamp 400 may include a UVE holder 428 configured to hold the UVE 424 in a desired position within the lamp envelope 402, wherein a portion of the UVE holder 428 is coupled to a portion of the mounting frame 410.
Referring to
A first leg 534 may depend from the first turn 642 and a second leg 536 may depend from the second turn 644. The first leg 534 may have a first distal portion 648 remote from the first turn 642, the first distal portion 648 defining a first attachment region 650 adapted for attachment to at least a portion of the mounting frame 410 (second electrical lead).
Similarly, the second leg 536 may have a second distal portion 652 remote from the second turn 644 and adjacent the first distal portion 648 of the first leg 534. The second distal portion 652 may define a second attachment region 654 adapted for attachment to at least a portion of the mounting frame 410 (second electrical lead). Additionally, the second attachment region 654 may be adapted for attachment to the first distal portion 648 and/or the first attachment region 650 of the first leg 534. The through passage 646 may define a substantially longitudinal axis A, wherein the first and second legs 534, 536 are substantially perpendicular to axis A. The first leg 534 may have a first length L1 and the second leg 536 may have a second length L2, wherein L1 may be approximately equal to L2.
As shown in
As shown in
The UVE holder 428 may include a single continuous wire, wherein the wire may include a flexible, resilient, and durable material configured to be bent and/or shaped into a desired dimension, such as the plurality of turns 640, as described earlier. The material may include molybdenum, for example. In one embodiment, the molybdenum wire may have a nominal 0.3 weight percent of La2O3 doping. Additionally, impurities within or on the wire should be less than 100 ppm. The wire diameter tolerance may be ±2.0%. The amount of surface carbon in one gram of molybdenum wire may not exceed 60 micrograms.
A UVE holder consistent with the present disclosure is configured to provide a more secure fit with less chance of UVE damage and/or breakage when compared with current UVE holders. For example, the second leg 536 of the UVE holder 428 may be configured to provide additional stability when torsion forces and the like are applied to the UVE holder 428 and/or UVE 424. Additionally, the plurality of turns 640 having a substantially similar inner diameter may allow a consistent and secure fit with the outer envelope 530 of the UVE 424.
Additionally, a UVE holder consistent with the present disclosure provides a minimum number of components and/or coupling points, resulting in less time required for assembly and less manufacturing costs. For example, the UVE holder 428 requires only a single weld (weldment 538) upon assembly, rather than two previously required with the prior art holding means described earlier. Additionally, the UVE holder 428 may be preformed prior to lamp assembly, rather than requiring formation during the lamp assembly process.
Consistent with one embodiment of the present disclosure, an ultraviolet enhancer (UVE) holder 428 may be configured to attach a UVE 424 having an outer envelope 530 to an electrical lead 420 of a lamp 400 and to retain the UVE 424 within the lamp 400 in a desired position. The UVE holder 428 may include a plurality of turns 640 comprising a first turn 642 and a final turn 644. The first and final turns 642, 644 may have a substantially similar inner diameter D defining a through passage 646 shaped to conformingly receive the outer envelope 530 of the UVE 424. The UVE holder 428 may further include a first leg 534 depending from the first turn 642, wherein the first leg 534 may have a first distal portion 648 remote from the first turn 642 defining a first attachment region 650 adapted for attachment to a lamp capsule electrical lead 410.
Consistent with another embodiment of the present disclosure, an ultraviolet enhancer (UVE) 424 and holder subassembly 428 may include a UVE 424 for a lamp 400, the UVE 424 having an outer envelope 530. The holder subassembly 428 may include a metal wire holder 428 for attaching the UVE 424 to an electrical lead 420 of the lamp 400. The metal wire holder 428 may include a plurality of turns 640 comprising a first turn 642 and a final turn 644. The first and final turns 642, 644 may define a through passage 646 shaped to conformingly receive the outer envelope 530 of the UVE 424, wherein the UVE outer envelope 530 may be disposed in the through passage 646. The metal wire holder 428 may further include a first leg 534 depending from the first turn 642 and a second leg 536 depending from final turn 644. The first leg 534 may have a first distal portion 648 remote from the first turn 642 defining a first attachment region 650 adapted for attachment to a lamp capsule lead 410. The second leg 536 may have a second distal portion 652 remote from the final turn 644, the second distal portion 652 extending in a similar direction to the first distal portion 648.
The following is a list of reference numeral used in the specification:
While several embodiments of the present disclosure have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified, unless clearly indicated to the contrary.
