DE1274229B - High pressure gas discharge lamp - Google Patents

Description

BUNDESKEPUBLIK DEUTSCHLAND DEUTSCHES WTW ^ PATENTAMT Int. CL:

EDITORIAL

HOIj

German class: 2If-82/01

Number: 1274229

File number: P 12 74 229.9-33 (W 39028)

Filing date: April 22, 1965

Display day:!. August 1968

The invention relates to a high-pressure gas discharge lamp with an elongated discharge vessel, which has a main body with a constant diameter, which is in a sealing fusible piece at both ends opens, and one filling from a selected one, the. Contains discharge sustaining substance, which must be kept at a high temperature during operation of the lamp, also with a the outer bulb surrounding the discharge vessel, in which a holder is arranged which holds the discharge vessel detected and supported on the fusible links, with heat traps over the closed Ends of the discharge vessel are attached, essentially all parts of each at this end cover the arranged electrode.

It is already known to modify high-pressure mercury vapor lamps by adding additives, in particular selected metallic iodides, includes in the discharge vessel. When operating such In lamps, the mercury, which has completely evaporated, usually provides the necessary voltage drop across the lamp, and the extra iodides improve the color and light output the discharge. Such lamps with additional filling are in »Illuminating Engineering Society, Paper 29 "under the title" Higher Efficiency Light Source Through the Use of Additives to Mercury Discharge ”, from September 1962, generally described.

In order for such discharge lamps to work properly with additional filling, the additive must be used during the Operation to be heated to a high temperature, so that it has a relatively high vapor pressure. Of the The vapor pressure of the additive is usually determined by the coolest part of the discharge vessel, and this coolest part is often at one end of the discharge vessel, especially when the discharge vessel is operated in the vertical burning position. It is desirable to have such To be able to operate lamps effectively in any burning position.

A discharge lamp is known (US Pat. No. 2 272274) in which the ends of the discharge vessel metallic caps are applied so far that they are essentially all Cover parts of the electrodes arranged on these.

There is also a high-pressure lamp with caps made of heat-resistant material known (United States patent 2,319,912). These caps cover the electrodes and prevent condensation from forming High pressure gas discharge lamp

Applicant:

Westinghouse Electric Corporation,

Pittsburgh, Pa. (V. St. A.)

Representative:

Dipl.-Ing. F. Weickmann,

Dipl.-Ing. H. Weickmann

and Dr. K. Fincke, patent attorneys,

8000 Munich 27, Möhlstr. 22nd

Named as inventor:

Charles R. Edris, Bloomfield, N. J .;

Hugh D. Millers,

West Caldwell, N. J. (V. St. A.)

Claimed priority:

V. St. ν. America May 19, 1964 (368 471)

Discharge entertaining filling at the ends of the discharge vessel.

It is also known (US Pat. No. 254 845) for high-pressure lamps with an outer bulb appropriate caps are to be provided at the ends of the discharge vessel. Here too they have Caps the purpose of preventing condensation behind the electrodes.

In these known discharge lamps, there is necessarily an air gap between the metal caps and the discharge vessel, since the discharge vessel and the metal caps are different Have coefficients of thermal expansion. However, the thermal insulation is achieved by the air gaps unfavorably impaired.

There is also a discharge lamp known (German Patent 597 916), in which a displaceable Metal jacket encloses the end of the discharge vessel. In addition, this coat comes with a covered with a heat-insulating layer. Despite this heat-insulating layer, however, there must be an air gap remain between the jacket and the discharge vessel, so that also in this known discharge lamp the thermal insulation and thus the yield of the lamp is adversely affected.

809 588/185

The object of the invention is to create a high-pressure gas discharge lamp with an additional filling which works with improved yield.

The invention is achieved in that the heat traps are a mat made of heat-resistant fiber mass have, which the gap between a retaining cap made of heat-resistant metal and the The covered part of the discharge vessel is packed tightly and its material is filled at the operating temperatures the lamp is not gas, is inert and does not react with the retaining cap and the discharge vessel. The heat traps according to the invention have the advantage that they do not have any air gaps from the discharge vessel to have. Furthermore, in the heat trap according to the invention, the mat adapts itself easily the irregular shape of the discharge vessel and thereby facilitates the attachment of the metallic Retaining cap.

The invention is based on the following description of preferred exemplary embodiments with reference to the attached Drawings more clearly visible. It shows

Fig. 1 is a side view, partly in section, a complete high-pressure discharge lamp with additional filling, with parts of the outer bulb broken away to show a cap in detail, FIG. 2 shows an enlarged cross-section according to FIG Line Π-ΙΙ in FIG. 1,

F i g. 3 shows an enlarged partial section along the line III-III in FIG. 1, the construction details of a Cap shows

F i g. 4 shows an enlarged section along the line IV-IV of FIG. 3, showing the details of the fastening a cap shows

F i g. 5 shows a section along the line V-V in FIG. 4, which illustrates a top view of a cap;

6 shows a mat made of heat-resistant fiber material, how it is used for insulation between the cap and the discharge vessel, and

F i g. 7 shows a stamped piece which represents an embodiment of the cap before it is around the end of the discharge vessel is lying around.

In the embodiment of the invention on which the drawings are based, corresponds to Lamp 10 of FIG. 1 in its construction of a customary high-pressure mercury vapor lamp, as described in U.S. Pat. No. 2,748,303, dated May 29, 1956 by Thorington. That However, the discharge vessel has been modified somewhat, as will be explained in greater detail later. The lamp 10 Mainly comprises a radiation-permeable, airtight inner jacket, the discharge vessel 12 made of quartz, polycrystalline aluminum oxide or another suitable material, at the ends the two working electrodes 14 are arranged such that a vapor discharge between them can be sustained. In the discharge vessel 12 are a mercury filling 16 and a small amount of an inert, ionizable ignition gas, for example argon. The mercury filling is available in predetermined quantities so that when operating the lamp after the mercury has completely evaporated, the appropriate voltage drop across the lamp and the correct energy supply to the lamp.

In one embodiment, 117 mg of mercury are enclosed in the discharge vessel 12, the has a volume of 23.5 ecm. The distance between the electrodes is 6.2 cm; the discharge vessel is filled with argon at a pressure of 20-25 mm Hg. Among the additives 18 that are in the discharge vessel may contain: thallium iodide, sodium iodide, and indium iodide; Further metallic iodides, chlorides or bromides can supplement or replace the additives mentioned can be used to achieve different discharge characteristics. In a special Example can be thallium iodide in an amount of

ίο 0.3 mg per ecm of the total volume and sodium iodide be contained in an amount of 1 mg per ecm of the total volume in the discharge vessel. A small additional amount of metallic thallium can possibly also be enclosed in the vessel be.

The discharge vessel has a main section (vessel body) 12 α with a constant diameter and opens at both ends into a sealing, flattened melt-down piece 12 b. The discharge vessel is designed for operation with an input power of 400 watts. A radiation-permeable, airtight outer bulb 20 surrounds the discharge vessel 12 at a distance. The electrodes 14 are connected to conductive leads 22 which are melted through the ends of the discharge vessel. Further feed lines 24 are melted down through the outer bulb 20 and are electrically connected to the feed lines 22 of the discharge vessel. They serve to connect the electrodes 14 to a conventional energy source, not shown.

A customary ignition electrode 26 is also arranged in the discharge vessel 12, which has a conventional starting resistor 28 is connected to one of the leads 24. The discharge vessel 12 is supported in the outer bulb 20 with the aid of a conventional holder 30.

According to the embodiment of the invention, as shown in FIGS. 1 to 5, a metal cap 32 is held on a cross strut 34 above each closed end of the discharge vessel 12. The two caps 32, which can be made of steel coated with nickel, for example, extend from the respective fused end 12 b of the discharge vessel so far along the vessel body 12 a that they essentially cover all parts of the electrode 14 arranged next to this end. This overlapping position of the caps 32 is shown in FIGS. 3 and 4 shown in more detail.
Between each cap 32 and the part of the discharge vessel covered by the cap, a mat 36 of tightly packed, heat-resistant fiber mass is inserted, which mat is shown in the expanded state in FIG. 6. The mat 36 consists of an inert substance which does not produce gas at the operating temperatures of the discharge vessel and does not react with the discharge vessel and the metal caps. As an example, the mats 36 may be made of aluminum silicate fiber or quartz wool, or other suitable materials instead.

In operation of the lamp 10, the caps 32 and the tightly packed mats 36 hold the in the vicinity of the Electrodes 14 return heat generated and thus prevent condensation of the discharge entertaining filling at the ends of the discharge vessel.

In an advantageous embodiment according to the invention, which the F i g. 3, 4, 5 and 7 show will the caps 32 in their position by the cross braces 34

held. Each metal cap 32 includes a first, annular portion 38 that encompasses the tubular body Surrounds to a certain extent. A second section of the cap is adapted to the end of the discharge vessel and consists of a number of juxtaposed, approximately trapezoidal members 40. At their base lines the trapezoids 40 are connected to the ring portion 38, and are near the baselines curved in such a way that they form a cover over the end of the discharge vessel. The caps 32 can be made of one continuous piece, but they preferably consist, as in FIG. 7th shown, from a metal strip which is bent so that it is attached to the discharge vessel 12 in the adapts to the manner described.

When operating the discharge lamps equipped with the caps 32 and the mat 36 with additional filling there is no tendency for the additive maintaining the discharge to condense the ends of the discharge vessel, regardless of which burning position the discharge vessel occupies. This increases the vapor pressure of the additive, so that the lamps with improved Working efficiency.

Claims (3)

Patent claims: 1. High-pressure gas discharge lamp with an elongated discharge vessel, the one Has main body with constant diameter, which at both ends in a sealing Melting piece opens, and one filling from a selected one, the discharge contains sustaining substance which occurs when the lamp is operated at a high temperature must be held, furthermore with an outer bulb surrounding the discharge vessel, in which a holder is arranged, which grips the discharge vessel at the melting pieces and is supported, wherein heat traps are attached over the closed ends of the discharge vessel are, which are essentially all parts of the electrode arranged in each case at this end cover, characterized in that the heat traps a mat (36) made of heat-resistant Have fiber mass which forms the space between a retaining cap (32) ίο heat-resistant metal and the covered one Part of the discharge vessel (12) fills tightly packed and its material at the operating temperatures the lamp is not gas, is inert and with the retaining cap (32) and the discharge vessel (12) does not respond. 2. High-pressure gas discharge lamp according to claim 1, characterized in that each metallic cap (32) has a first, annular portion (38) which is a piece of the vessel body (12 a) surrounds, and a second section which adapts to the end of the discharge vessel which consists of a number of adjacent trapezoidal members (40), those at their baselines with the ring section (38) are connected and next to the baseline are bent in such a way that they come to the end of the Adapt the discharge vessel. 3. High-pressure gas discharge lamp according to claim 2, characterized in that the metal caps (32) consist of a metal strip which is bent according to the shape of the discharge vessel and which extends at its ends overlaps. Considered publications: German Patent No. 597,916;
U.S. Patents Nos. 2,254,845, 2,272,274,
319 912. 1 sheet of drawings