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Publication numberUS3883763 A
Publication typeGrant
Publication dateMay 13, 1975
Filing dateSep 16, 1974
Priority dateSep 16, 1974
Publication numberUS 3883763 A, US 3883763A, US-A-3883763, US3883763 A, US3883763A
InventorsKearney Joseph P
Original AssigneeWestinghouse Electric Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Self-controlled arc stream in gaseous discharge lamps
US 3883763 A
Abstract
A discharge lamp with minimized upward bowing of the arc in which conductors carrying full arc current are placed in close proximity above and below the arc tube. The conductors run parallel with the longitudinal axis of the arc tube and the conductor (or conductors) above the arc are electrically connected in such a manner as to carry full lamp current in the same direction of the arc (thus repelling the arc in a downward direction) and the conductors below the arc tube are electrically connected so as to carry full lamp current in the opposite direction of the arc (thus attaching the arc downward).
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Description  (OCR text may contain errors)

United States Patent Kearney i 1 SELF-CONTROLLED ARC STREAM IN GASEOUS DISCHARGE LAMPS [75] Inventor: Joseph P. Kearney, Teuneck, NJ.

[731 Westinghouse Electric Corporation,

Pittsburgh, Pa.

Sept. 16, 1974 Assignee:

US. Cl. .1 313/154; 313/25; 313/161 Int. Cl. H01] 17/14 Field of Search 313/156, 161, 184, 25,

References Cited UNITED STATES PATENTS 3,562,583 2/1971 Zollweg cl a1. 313/161 X Primary E.rurnirwr-Palmer C. Demeo Attorney, Agent, or Firm-R. A, Stoltz [57] ABSTRACT A discharge lamp with minimized upward bowing of the arc in which conductors carrying full arc current are placed in close proximity above and below the arc tube. The conductors run parallel with the longitudinal axis of the arc tube and the conductor (or conductors) above the are are electrically connected in such a manner as to carry full lamp current in the same di rection of the are (thus repelling the arc in a down ward direction) and the conductors below the arc tube are electrically connected so as to carry full lump current in the opposite direction of the are (thus attaching the arc downward).

4 Claims, 1 Drawing Figure 18 r 36 M I /2 F; 40 r 2 f l .l. I 1L SELF-CONTROLLED ARC STREAM IN GASEOUS DISCHARGE LAMPS BACKGROUND OF THE INVENTION The present invention relates to controlling the arc bowing normally encountered in arc discharge lamps. When a discharge lamp is operated with the arc-tube in a position other than essentially vertical, and in particu lar when the arc tube (and arc) are in a horizontal or near horizontal position, the arc discharge does not remain along the central axis of the arc tube during continued operation, but bows upward within the arc tube. This are bowing can and often does result in early lamp failure through excessive heating of a particular portion of the arc tube wall.

It is well known that in high pressure mercury vapor lamps operated at high power levels in a horizontal burning position, such lamps tend to have a hot portion of the arc tube. Electro-magnetic means have been used to deflect the arc-discharge down into a more central portion within the arc tube by directing the magnetic field transverse to the arc current direction wherein the inner-action of the arc discharge current and magnetic field results in a downward force on the arc.

US. Pat. No. 3,562,583, issued to Zollweg and Burnham on Feb. 9, I971 describes a magnetically rotating, constricted arc discharge device having electromagnetic means to rotate a resultant magnetic flux generally transverse to the arc discharge to cause the arc discharge to rotate about the longitudinal axis of the arc tube and thereby avoid destructive arc bowing.

The use of a separate electromagnet consumes extra power, takes up a great deal of space, and can block a large amount of the light emitted from the arc tube. Permanent magnets can also be used, but they also are bulky and generally block a significant amount of light.

SUMMARY OF THE INVENTION The instant invention provides an inexpensive tech nique for stabilization of the arc ofa gaseous discharge lamp without drawing current in addition to lamp current or blocking a substantial amount of light.

The invention is (in combination with a discharge lamp of the type wherein an elongated arc tube having a main electrode in either end, between which electrodes an arc is established during operation, and which arc tube is contained within a light transmitting outer envelope) the improvement which comprises; at least three refractory metal conductors located inside of the outer envelope and outside and in close proximity to the arc tube, which conductors run generally parallel to the longitudinal axis of the arc tube and are electrically connected in series with the main electrodes. The conductors are electrically connected such that when the lamp is operated with the arc other than substantially vertical, at least one of the conductors is generally above the arc tube and is carrying full arc current in the same direction as the arc and at least two of the conductors are generally below the arc tube and are carrying full arc current in the opposite direction of the arc. The magnetic effect from the current in both the conductors above the arc tube and the conductors below the are tube tends to counteract the natural upward bowing of the arc.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, reference may be had to the exemplary embodiment shown in the accompanying drawing in which:

The sole FIGURE is a side elevational view of a discharge lamp constructed in accordance with the pres ent invention, with parts of the outer envelope broken away.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the sole FIGURE there is shown the general arrangement of a high pressure mercury vapor discharge lamp within which refractory metal conductors in close proximity to the arc tube are used to stabilize the arc. The lamp, generally designated 10, includes an outer light transmitting envelope 12 which is sealed to a mogul base 14. Other types of bases such as a mogul bipost may also be used, as it should be noted that proper orientation of the refractory metal conductors (ie having the conductor which carries current in the same direction as the arcs located above) is essential to proper operation. Mounted within the outer envelope l2, and spaced therefrom, is an arc tube 16. The are tube I6 is mounted within the outer envelope [2 by a two-piece frame, comprising a base-end frame 18 and a dome-end frame 20. Sealed within the arc tube 16 and disposed at opposite ends thereof are a pair of main electrodes 22 and 24. The base-end main electrode 22 and the dome-end main electrode 24 are sealed through the ends of the arc tube 16 by conventional ribbon seals 26. A starting electrode 28 is also sealed to the arc tube adjacent to base-end main electrode 24 by means of a ribbon seal 26.

A pair of lead-in conductors 30 extend through a conventional reentrant stem press 32 connected to the mogul base 14, which in turn is connected to a conventional power source through a ballast 34 in the well known manner.

A starting resistor 36 is connected between one of the lead-in conductors 30 and the starting electrode 28.

A top refractory metal conductor 38 is positioned above the arc tube 16. Bottom refractory metal con ductors 40 are positioned below the arc tube 16. One end of the top conductor 38 is electrically connected to the one of the lead-in conductors 30 and the other end of the top conductor 38 is electrically connected to one end of one of the bottom conductors 40. The other end of that same bottom conductor 40 is electrically connected to the base-end main electrode 22. The other bottom conductor 40 is electrically connected on one end to the other lead-in conductor 30 and on the other end to the dome-end main electrode 24.

It will be noted that some lamps of the prior art have used two-piece frames 18, 20 as shown in the Figure while others have used one-piece frames. Typically, when one-piece frames are used, the current to the dome-end main electrode is carried through the frame. The instant invention can be used with either one-or two-piece frames, but the two-piece frame, as shown in the FIGURE, is preferred.

Phosphor coatings are commonly used on the interior surface of the outer envelope of high pressure discharge lamps, and, if desired, can be used in conjunction with the instant invention. Except for the refractory meta] conductors 38, 40 used in the instant invention to counteract the arc bowing, the lamp operation is essentially conventional. A description of the config uration and operation of a conventional high pressure discharge lamp may he found in US. Pat. No.

Eff-183d} issued to ihorington on May I IJ'So.

The in tant invention permits a gaseous discharge light source to operate in the borivontal mode more el ficiently and more safely since it minimi/cs the natural bowing of the arc stream, which bowing normally causes the are to come into very close proximity of the wall of the are tuhe l6 (and sometime actually touching it). When using this invention, the arc stream is more centrally located keeping a more uniform temperature and more of the light producing materials in a vapor state. resulting in better efficacy. The more central location of the arc prevents violent failure which can he caused by the arc stream coming very close to or actually touching the arc tube 16. Although the imention is intended for use primarily when the are tube 16 is operated in other than a vertical manner, the invention also assists in stahilizing the are when the arc is vertical.

To provide substantial stabilization. it has heen found that the refractory metal conductors 38 and 40 must he in close proximity to the arc tuhe. (icncrally the con ductors must be within a quarter of an inch and prefer ably within it i s of an inch ofthe arc tuhe substantially throughout the entire arc length. These conductors 38, 4t! should he as close as practical to the arc tube l6 and can actually touch the arc tube 16. Because of the tenr per-attire on or near the arc tube 16 being quite high, it is necessary to use a refractory metal for such conductors. In order to minimize the light blocked by the conductors 38, 40 it is also desirable that they be of small diameter lrihhon conductors can also be used and should be positioned with their larger cross sectional dimension in radial relationship with the are such that they proiide a minimum shadowing of the light emitted by the arc].

The refractory metal conductors 38, 4!) are connected in series relationship with each other and in serics relationship with the arc current. This can he :chieied in a number of manners. For example, one lcadin conductor 30 can he connected directly to the base-end main electrode 22. lhe other lead-in conductor 30 is then run under the are tube 16 and past (but not connected tot the dome-end main electrode 24. back above the are tuhe 16 past (but not connected to} the hase-end main electrode 22 and then under the arc tube to back to and connected to the dome-end main electrode 24 (in this configuration the three conductors 38. 40 can he formed by a single piece of wire).

Another alternatiie {the alternatiie shown in the FIGURE! is to run a refractory metal conductor 40 from one of the leadin conductors underneath the arc tuhe l6 and connect it to the domc-end main electrode 24. Refractory metal conductor 38 is run from the other lead-in conductor 30 above the arc tuhe l6 past lhut not connected to) the dome-end main electrode 24 and then run (as refractory metal conductor 40) under the arc tube 16 back to and connected to the base-end main electrode 2. This configuration has the advantage that the refractory metal conductors 38, 40 can be conveniently supported by a single additional support tat the point at which the conductor is going past, but not connected to. the dome-end main elec trode 24).

Ill

(it t Such lamps are generally run on ac current and the direction of the current reverses every half cycle both in the are, and in the refractory metal conductors 38, 4t), During both halves of the cycle, the current in the top refractory metal conductor 38 is in the same direction as the arc current and therefore always repels the are downward. The currents in the bottom refractory metal conductors 40 are always opposite the are current and therefore are always tending to pull the arc downward.

Configurations in which more than three conductors are used will function in the mode of the invention although it will he noted that the use of more conductors tends to block more of the light emitted from the arc tube. It can be seen that a five refractory metal conductor configuration in which there are two top conductors 38 and three bottom conductors 40 can be electrically connected in a manner similar to the aforementioned three refractory metal examples. The two top conduo tors 38 and three bottom conductor 40 configuration can he produced by, for example, connecting the baseend rnain electrode 22 directly to one of the lead-in conductors 3t) and running a piece of refractory metal wire [which will form the five refractory metal conductors) from the other lead-in conductor 30 under the arc tube In, past the dome end electrode 24, above the arc tube 16 back past the haseend electrode 22, under the arc tube 16 past the domeaend eiectrode 24. above the are tube 16 past the base-end electrode 22, and under the arc tube 16 and connecting to the domeend main electrode 24. [t can be seen that even more fie seven) refractory metal conductors can he used in a similar manner.

While lamps can he fabricated with a single refrac tory metal conductor close to and below the are tuhe. experiments have shown that such a configuration is unsatisfactory as it does not provide adequate control of arc bowing.

The instant invention can he used with high pressure mercury lamps and with halide lamps (it should be noted however that sodium containing lamps when used with the instant invention will generally experience increased photo-electric problems due to the close proximity of the conductors to the arc tube 5. The instant invention provides a cheaper and more convenient configuration than units in which magnets are used.

l claim.

1. In combination with a discharge lamp of the type wherein an elongated arc tube having a main electrode in either end, between which electrodes an arc is cstablished during operation, and which are tube is contained within a light transn'iitting outer envelope, the improvement which comprises:

at least three refractory .rnetui conductors located inside of said outer emelope, and outside and in close proximity to said are tube and running generally parallel to the longitudinal axis of said are tube, said conductors being electrically connected in series with said main electrodes and being electrically connected such that when said lamp is operated with said are other than substantially vertical, at least. one of said conductors is generally above said are tube and is carrying current in the same direction as said arc, and at least two of said conductors are generally below said are tube and carrying eur rent in the opposite direction as said are, whereby the magnetic effect from the current in both the cunduetur ahuve the arc tube and the euntluetors below the are luhe tends to counteract the natural upward bowing of the arc.

2. lhe lamp of claim I. wherein three refractory is tungsten metal cumlucturs are used.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2930920 *Nov 2, 1956Mar 29, 1960Engelhard Ind IncElectrical discharge lamp
US3153169 *May 21, 1962Oct 13, 1964Patra Patent TreuhandDischarge lamp
US3562583 *Jan 27, 1969Feb 9, 1971Westinghouse Electric CorpMagnetically rotating constricted arc-discharge device
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3995928 *Jan 13, 1975Dec 7, 1976General Electric CompanyHigh pressure metal halide lamp with electron collector
US4061939 *Aug 2, 1976Dec 6, 1977General Electric CompanyLow noise sodium vapor lamp for sonic pulse operation
US4064418 *Nov 4, 1975Dec 20, 1977Westinghouse Electric CorporationControlled arc stream in high intensity discharge lamps
US4281267 *May 14, 1979Jul 28, 1981General Electric CompanyHigh intensity discharge lamp with coating on arc discharge tube
US4311943 *Nov 13, 1979Jan 19, 1982Spellman High Voltage Electronics Corp.Fluorescent lamp with arc spreading with recombination structures
US5997162 *Mar 13, 1998Dec 7, 1999Osram Sylvania Inc.Horizontal HID vehicle headlamp with magnetic deflection
US6043614 *Jun 18, 1998Mar 28, 2000Osram Sylvania Inc.Alternating current hid lamp with magnetic deflection
WO1997032337A1 *Feb 28, 1997Sep 4, 1997Gernot K BrueckSimple wiring method for high-pressure mercury vapour lamps in tanning devices
Classifications
U.S. Classification313/154, 313/25, 313/161
International ClassificationH01J61/02, H01J61/56, H01J61/50, H01J61/00, H01J61/82
Cooperative ClassificationH01J61/822, H01J61/56
European ClassificationH01J61/56, H01J61/82A
Legal Events
DateCodeEventDescription
Mar 30, 1983ASAssignment
Owner name: NORTH AMERICAN PHILIPS ELECTRIC CORP.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:004113/0393
Effective date: 19830316