DE2142687A1 - Electric lamp with pinch foot - Google Patents

Description

PATENT LAWYERS

DR.CLAUS REINLÄNDER August 25, 1971 DlPL-ING. KLAUS BERNHARDT

D - 8 MONKS 60 21A9R87 THEODOR-STORM-STRASSE 18e £ I * + £ g O /

S6 P127 D

GTE Sylvania Incorporated Wilmington, Delaware, USA

Electric lamp with pinch foot

Priority * 28 "August 1970, USA, Ser. No 67 699

The thin, heat-resistant metal hand is completely wrapped in embedded in the pinch foot of a glass lamp bulb with a high silica content »One end of the ribbon is safe in a longitudinal slot of a lamp feed wire held so that a physical and electrical connection is made between the tape and the lead wire will.

Background of the Invention "

This invention relates to lamps having a pinch foot at one or both ends and a refractory metal band embedded in the pinch foot, and more particularly to an embedded connection between the band and the lead wire or rod.

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Lamp bulbs "that work at high temperatures" are usually made of high-melting glass with a high silica content. Such glasses can be, for example, quartz molten silica, Vycor (a glass with about 96? S silica halt) and the like.

Such lamp bulbs are usually closed with a rubber foot at one or both ends. The squeeze foot is formed in that the open end of a tubular lamp bulb extends to the softening point of the glass. is warmed and the softened end is pressed between two jaws.

Examples of pinch-type lamps of this type to which the invention relates are halogen-tfolfram-Lainpen and the discharge vessels of arc discharge lamps, for example high-pressure mercury lamps and metal halide lamps.

Pinch feet are used in the bulb of such lamps in order to prevent failure of the seal due to the thermal expansion of the glass or the metal conductor embedded therein. The high operating temperature of the lamps prevents the use of fused wires, such as those commonly used in incandescent lamps and fluorescent lamps, the operating temperatures of which are significantly lower.

In the manufacture of pinch-type lamp bulbs, it is known to use a thin, heat-resistant metal band to establish the electrical connection between the outer lead wires and the inner wires or electrodes. The use of thin ketallic ribbons, and the reasons for doing so, are described in U.S. Patents 1,271,245 and 2,667,595, when also the ribbons described therein are flattened portions of a single conductor running completely through the bulkhead. In general

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However i / eroen the tape and the wire of different metals produced, the kandaetall due to its' e · -rbeitbarkeit is chosen, usually molybdenum _fl and • e - ;. all of the inner wire is chosen due to the heat resistance, usually irolfram.

Generally, the tape is connected to the lead wire by stapling or stapling. ISn such a compound I: turn off a thin film of a geedgnsten Meinl, usually platinum _f between the tape and the Zuleitunge "ciröiit placed, and the whole v / ill be between two resistance" - brought ßchvreißelektroden "The whole wii * d between the Electrics are pressed and sufficient electric current is sent so that the elements are heated and adhered to one another, at least in part by melting the tin foil. The connection between the tape and the lead wire can be improved during the crimping process wsrden _e vewii the silica glass is hot enough to melt additional? lacin

A similar soldered or stapled connection is for Satisfactory training cases, but has some ; s; lle that should be avoided by the invention »

Soldering or tacking can cause a recrystalline a part of the molybdenum strip that is located directly between the resistance welding electrodes.

The recrystallization results in a weakening of the tape, which can then physically break when exposed to the thermal alternating treatment that occurs during normal lamp operation. The recrystallization can also have a high electrical resistance between the

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ORIGINAL INSPECTED

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Lead wire and the tape cause "the through dea raised resistance generated heat causes sins waiters Yarsclilechterung with curved saws and finally a®a Failure of the sealing

A second disadvantage lies in the fact that the solder occasionally does not flow sufficiently * to ensure an adequate, low coatact resistance * A pimki-shaped contact _e - ia in contrast to the desired flat contact; / bring about

EIa v / Eiterer disadvantage of the known Seelmife is clif- · MiSgI iah "ness that the solder with the Laspenfüllis ^ vo: ^A 3iaod" nen substances react canoe, "Such a reaction is © sögliefe _Θ because the Giss no hermetic seal with forms tung wires S, the hermetic seal is formed in the region of the thin strip "Accordingly, it is possible gaseous substances ₉ the narrow passage zn pas?" _s that exists around the lead wire »and: m & r up to sum connection of the tape to the end of the lead wire,

The Entladungsg © fäBs ύοϊι metal halide Lampea haboa at · = play, a EOllung with lichtemittiereaden Ms-oallea (for example, US Patents 3,234,421, 3 JJL 261 _c 3407327). During lamp operation, the metals are in a gaseous state, as halides. In the gaseous state, the metal halides can penetrate the seal and react with the solder, so that an alloy is formed, which has a eutectic temperature _ff . © di lower * than is di © normal operating temperature of the sealing · Instead, a specific light-emitting ^ metal such as scandium, with deia glass reagi & ren _e so that Siliziumiodid is formed, "which in turn adversely

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Platinum reacts so that a platinum ^ SiXizit material is formed \ /. 1Μ. This material can lead to a failure of the . '■' ■ y.-j.stibvmg in the described method.

the

üi'fctö lamp with a QuetaehfuQ according to the invention has Eir-m hitEöst-resistant metal wire or tab, usually ¥ olfrain, which is placed in a glass flask with high pebble is, for example, the lamp bulb of a high-temperature glow tube or the discharge tube 3.1 c ..:; v · Arc discharge lamp · One end of the hitaebestMndigea Kö'calldraU'iBs or rods embedded in the pinch foot " te: -, and the other end is with a filament or one Electrode connected in the flask.

embedded end of ixitzo-resistant metal wire

The rod has a longitudinal slit, one end of a thin, heat-resistant metal band is held securely inside the sciilitz, the band itself being completely embedded in the foot , Im '-hih \ itv>. held.

Be! According to the invention, a longitudinal slot is first formed in one end of the heat-resistant metal wire. This slot can be formed, for example, by grinding, milling, electrical decomposition, 3chy. !! machining or a laser beam, of course other methods can also be used.

The borehole slot must have a sufficiently wide opening to allow insertion of the tape, and a sufficient one

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Have depth to provide an adequate area of contact between to expose the rarity of the slot and the tape. Bine adequate contact area is necessary to have a niac ^ i = to obtain electrical contact resistance "

After the tape has been inserted into the slot *, the sides of the slot are physically pressed together, preferably with heat, but at a temperature below the recrystallization temperature of the occurring metals o the pressure exerted must be high enough to keep the reeds; to deform and close, but must not be so large that _c seis to bring the metal with a lower elastic limit zvm Jumps, v or breaking "

When connecting metals with different elasticity limits, the metal with a higher EIa ^ limit of elasticity brought to a higher temperature than the other metal. The heating and the '' Connection also in an inert or reducing atmosphere in order to prevent oxidation of the metals ο

The invention is to be explained in more detail with reference to the drawing

1 and 2 an arc discharge lamp or a tungsten-halogen lamp with the invention Squeeze;

3 and 4 are exploded views of a slotted rod and a heat-resistant metal band before and after closing the Slot on the tape.

The lamp shown in Fig. 1 has a glass bulb 1 high silicic acid content, the oddball feet at both ends 2 has. In the piston 1 there are electrodes 3 at each end

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arranged? these electrodes consist of tungsten filaments 6 which are mounted on tungsten rods 7. In addition, there is 3: a stator electrode 4 at an end of the piston 1 in the; ^T "* j: arranged e" iner electrode 3. The gate electrode 4 stands from the inwardly projecting end of a tungsten rrfar * ¹ J ⁵ S * tal-bar 8..

Thin molybdenum strips 5 are embedded in the pinch feet 2, one strip for each electrode. A compound zwisehe & the respective belt 5 and the corresponding tungsten rod 7, the end eii ■ * "YuV 6. & T forming the Quetschfußes 2 by using -, - ■ la π 5 ipreöen in a slot at the end of the rod and together ■ TK ^ becoming the Sch3..itzseiten produced "the other end * 3aes sand can then follow the same procedure état äußs * ■ • ro 2uleituDgsdrähten connected the famous Lötverfct.! r-.Λ kami but also to prepare the compound of the band sit c / .-m outer lead _{wire should be used t} because the Böfc-Rostesperatur of the seal at this point can be low to allow such a connection

For the same reason, soldering can be used _t d & s yiu. to be connected to the stater electrode 4.

the squeeze clip feet 2 have been shaped »will be the Eel« loergepumptp filled and sealed »\ rio that at the is known.

".is. Willem embodiment of a 100 watt arc lamp" 94 m long, which was manufactured according to the invention, had a diameter of 1.15 am (45 mils %. According to FIG. 3, a slot 9 was diametrically formed at one end da & ötabes 7; the slot had a thickness of G # 13 mm (C nils) and a depth of 1.52 to 2.03 mm (CO - CO mils} .. Sin rectangular molybdenum tape 5 about 5 χ 10 aaa (3/16 * χ 3/8 * 3 in the lutte a strength of about 0.033 as (ettm 1.3 al *

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BATH ORIGINAL

The long end of the band 5 was inserted centrally into the slot 9, and the rod was then placed between two welding electrodes. The welding electrode ?! consisted of thoriated tungsten and had a diameter of about 1.6 mm (1/16 "} ·

The rod 7 was so tet between the welding electrodes A's that "if this -were ₉ closed they s.ILb-3 λ> loan normal closing force on each side 10 of the ₅ 5e 9 exercised. A closing force of 3 kg (7 pounds) vnxrde placed between the welding electrodes, while sufficient electric current was passed to heat the slotted part of the rod 7 to about 1500 to 160o C ^0. The heat and pressure were sufficient to deform the sides of the slot and close securely against the molybdenum ribbon, as shown in FIG. 4, but not sufficient to cause the wolf rod to recrystallize. The pressure was also insufficient to extrude the molybdenum tape or to cause it to jump ”. Before closing the slot of the heat transfer between the rod 7 and the tape 5 was bad _s so that the belt was not heated to the same extent as the rod 5. 7

During this process the whole thing was enveloped with molding gas (15 % hydrogen, 85 % nitrogen) in order to prevent oxidation of one of the metals.

In the known soldered connections, there were irregular surfaces between the rod and the tape, and in contrast, the invention produces a more uniform connection and has some unexpected advantages. First, the stresses exerted on the glass by the connection are reduced. Second , the speed at which the lamp is evacuated during suction and filling is increased.

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Fig. 2 shows an example of a Yfolfram halogen lamp with a seal according to the invention. The lamp has a piston 11 made of glass with high silica content which sinen pinch 12 having at one end, wherein a gewendeltar Volframdraht 13 is disposed in the piston 11 and to a Lampenfülluug _s containing halogen ", Dar wire 13 waist a coiled leg 14 on each end "and both soles 14 reach into the pinch foot 12" an ¥ olfram rod 16 is securely inserted in each twisted leg 14, the end of the rod 16 protrudes slightly over one end of the leg 14 and is slit ·

The pinch foot 12 is embedded with two molybdenum cells 15 at a distance from one another. Each tape 15 is secured in the slot else einas • rod 16 in the manner described ¥ "An outer 2uleitungsdraht 18 is connected to each belt 15 to ensure wa for connection to an external power source"

am to reduce the electrical contact resistance between the slotted rod and the metal band to an ITj η 1 mim "* it may be desirable" to fold the end of the band back onto itself and insert the folded end into the slot before closing. The length of the folded part only needs to be approximately equal to the depth of the slot. The slot would then have to be widened slightly to allow the folded end to slide in. However, the slot need not be wide enough to break the metal when the sides of the slot are pressed and closed.

- Claims -

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Claims (7)

■ j PI 27 D Claims Electric lamp consisting of a bulb with a high Kleseleräegehalt, which has at least one pinch foot, in which at least a thin, heat-resistant metal band and a lead wire or rod are embedded "which extends into the bulb, thereby geke η r, - shows that the wire or rod has a slot at the embedded end, the sides of which are fixed to one end of the belt are closed, so that an electrical connection low resistance between the band and dam Bradh .; or staff consists » 2. Lamp according to claim 1, characterized in that the strip consists of molybdenum 3. Lamp according to claim 1 or 2, characterized in that the lead wire or rod from l'folfram consists. 4. Lamp according to claim 1, 2 or 3 »characterized in that one end of the tape is on itself is folded back. 5. A method for producing a lamp according to any one of claims 1 to 4, characterized in that a longitudinal slot is formed in one end of a lead wire or rod, one end of a heat-resistant metal strip is inserted into the slot, the sides of the 209810/1323 - Slit on the tape are closed and the tape is embedded in a pinch foot of a lamp bulb. 6. The method according to claim 5 »characterized in that the slot by pressing together the slot sides is closed with simultaneous heating. 7. The method according to claim 5 or 6 for producing a lamp according to claim 4, characterized in that that the end of the tape is folded prior to insertion into the slot. 209810/1323 1% Blank page