FR2474241A1 - INCANDESCENT LAMP WITH CURRENT INPUTS OF NON-METALLIZED COPPER - Google Patents

Abstract

LAMP CONTAINING RIGID CURRENT INPUTS IN NON METALLIZED COPPER. IT INCLUDES A GLASS BULB 11 CONTAINING A FILAMENT 12 SUPPORTED AND POWERED BY CURRENT INPUTS 13, 14 IN NON-METALLIZED COPPER THROUGH THE FOOT 15 AND AN ALUMINUM AND ZIRCONIUM GETTER 30 APPLIED TO THESE CURRENT INPUTS 13, 14. APPLICATION TO LAMPS WITH GASEOUS ATMOSPHERE.

Description

The present invention relates to incandescent lamps

  gas atmosphere and more particularly

  incandescent lamps with gaseous atmospheres having

  internal flow of unmetallized copper and an aluminum and zirconium getter applied to them to rid the atmosphere of the lamp of the deleterious gases which

  otherwise erode and contaminate the filament.

  Incandescent lamps usually have a bulb in which a foot is sealed. Current inputs, drowned and crossing the foot to allow the

  external electrical connection of a filament, connect

  and mechanically support this filament. The entrees

  current must have a high conductivity while pre-

  having sufficient rigidity to adequately support the filament. Medium- and low-power gas-filled lamps typically use copper wires or a suitable fuse from the metal cap to

  pinching of the foot, composite wires or Dumet in the pin-

  cement and nickel-plated copper wire from the nip to the filament.

  The Dumet composite wire in the nip consists of a nickel-nickel core encased in a copper sleeve and has substantially the same coefficient of expansion as the glass of the nip and allows for hermetic sealing. The internal current inputs of the filament, that is to say those going from the nip to the filament, are subjected to the atmosphere of the lamp and can therefore directly affect the operation of the filament. Also, these current inputs

  must be of a material which has a rigidity

  substantial capacity to support the filament and a conduc-

  high electrical tivity. Internal current inputs are generally nickel, nickel-plated iron, nickel-plated copper or

  molybdenum. In particular, these metals are less likely

  oxidation and, therefore, do not introduce contaminants into the lamp bulb. However,

  Current inputs made of nickel and nickel-plated iron are detrimental to

  This is because the nickel migrates into the tungsten filament and weakens it, causing the lamp to die prematurely by breaking the filament close to the filament attachment. Bare copper wire has not so far been used in gaseous atmosphere lamps because, during the sealing of the current entry in the nip, this current input is subjected to a high heat and, therefore, the copper oxidizes to form a copper oxide coating on this current input. Generally, a gas atmosphere lamp contains a small percentage of hydrogen or hydrogenated compounds which reduces the copper oxide and forms water vapor which activates the well-known water cycle in which tungsten is transported from the water. hot filament on the cooler wall of the bulb where it is deposited. The water cycle reduces the life of the lamp by erosion of the filament and in addition decreases the luminous flux of the lamp by blackening the wall of the bulb. In the prior art, metallized internal current inputs

  copper, for example with nickel, to prevent the oxidation of

  copper during both the manufacture and operation of the lamp. The small amounts of nickel oxide that are produced are less likely to be

  reduced by free hydrogen gas. However, metallization

  Nickel creates other problems in the lamp.

  The present invention uses current inputs

  bare copper in the lamp with an aluminum getter-

  zirconium which is applied to the internal current in the vicinity of filament fasteners for the sorption of

  which adversely affect the operation of the filament lamp

  and more particularly for the sorption of

  afraid of water. The getter is usually made of powders

  of aluminum and zirconium which represent, respectively,

  18% and 82% by weight, suspended in an acetylene binder.

  amylate and nitrocellulose and is applied to

  current of the lamp in the vicinity of the filament fasteners.

  In one embodiment, a thickness of about 0.25 mm of getter is applied to the current inputs. The high temperature produced by the active filament both aluminum

and zirconium.

  Generally, aluminum acts as a chemical getter that forms aluminum oxide with oxygen

  or the water vapor of the atmosphere of the lamp.

  Zirconium is a "solution" getter whose surface adsorbs a gaseous impurity which then diffuses

  inward forming a solid solution with the material

  getter's money. As a result, zirconium has a prolonged duration of activity and is particularly effective in removing oxygen and hydrogen from the lamp atmosphere. The getter materials are applied to the current inputs before the foot is sealed in the bulb of the

  lamp and, therefore, the binder materials are

  pores of current inputs by the heat of

  of the lamp, further reducing the risk of contamina-

lamp.

  The aluminum-zirconium getter of the present invention

  vention allows the use of non-current copper

  metallized in incandescent lamps with

  zeuse. These getter materials also allow the use of

  a dispersion-reinforced copper current inlet for rigidly supporting the sealing temperatures necessary to form tight seals

  between the current inputs and the pinch.

  Accordingly, the present invention aims to

  allow the practical use of rigid current inputs

  unmetallized copper in the bulb of an incandescent lamp and thus eliminate the need for

  additional filament and current inputs.

  The following description refers to the figure

  which represents an incandescent lamp according to the

present invention.

  The lamp 10 shown in the figure comprises a sealed glass bulb 11 containing a filament 12,

  tungsten, which is attached and electrically

  at the inner ends of the current inputs 13 and

  14 that pass through the glass foot 15 itself.

  2474241li even hermetically sealed in the neck 17 of the bulb Il and protruding internally in this bulb. The bulb

  waterproof It is filled with gas by an exhaust pipe 18 which

  The end of the exhaust pipe 18 is closed by a sealing seal 19 after the appropriate atmosphere of the lamp, such as an inert gas, has been introduced.

  a mixture of argon and nitrogen, in the bulb 11 of the lamp.

  For the sake of simplicity, the lamp has been illustrated as a single filament lamp having two contacts or terminals. The bulb 11 of the lamp is glued to a base 20

  provided with the appropriate number of terminals for the ex-

  lack of current inputs 13 and 14. More specifically

  the current input 13 is connected to the shell 20 of the base while the current input 14 is connected to a

  eyelet 21 of the base which is isolated from the hull.

  During the manufacture of the lamp 10, one of the

  The most difficult is the sealing of the current inlets 13 and 14 in the glass foot 15. The current inlets 13 and 14 generally comprise a section of composite wire such as Dumet which is sealed in the nip 22.

  The inner ends 25 and 26 of the neck entries

  13 and 14 respectively are crimped or attached to

  turn of branches 27 and 28 of the tungsten filament 12 and

  maintain the filament 12 in structural and electrical connection

  between the current inputs. The filament 12 can

  be a single-wire, spiraled, coiled or tris-

  pirated, the current inputs 13 and 14 being attached to the

  wire not spiraled or at first, second or third spiraling.

  US Patent No. 4,131,819 discloses the use of current inputs having a particular rigidity, US Pat. No. 4,138,623 discloses the use of dispersion reinforced copper for the inner and outer conductors of an electric lamp. and US Patent No. 4,208,603 suggests the use of dispersion-reinforced copper free of a metal exterior to the copper matrix, more commonly known as unsheathed dispersion reinforced copper. All of the above current inputs are nickel plated in a manner well known in the art to prevent oxidation of the lamp. If we combine the teachings of the above patents, it appears that rigid current inputs eliminate the

  need for support and attachment wires anchored to a

  tone of glass in the lamp; disperforced copper

  sion forms a desirable rigid current input which

  must be nickel plated to avoid contamination of the

  mosphere of the lamp; unsheathed dispersion reinforced copper also provides a rigid current input which further allows for improved bonding between the nickel plating and the copper of the current inlet to further reduce the risk of contamination by oxides in the

  lamp and the migration of nickel into the tungs filament

Tene.

  On the contrary, the present invention teaches the eli-

  the nickel migration problem and the embrittlement of the tungsten filament through the use of non-metallized copper current in combination with an aluminum-zirconium getter in the vicinity of the nickel plating. tungsten filament. Copper oxide is formed during treatment

  and the handling of unmetered copper current inlets

  tallisé. This copper oxide can be reduced, by means of

  example of hydrogen gas that may be present in the atmosphere.

  hen of the lamp either as an impurity or as a filling gas, and which forms water vapor

  in the lamp. As is known, water vapor attacked

  that and erodes the tungsten filament according to the water cycle well known and exemplified by the reaction below: On the hot filament W + HO WO + H On the wall of the bulb WOx + H - W + H20 o W is tungsten. We do not know the exact nature

tungsten oxides formed.

  The present invention provides a 2474241 i and zirconium aluminum getter which is applied to each of the inputs

  current 13 and 14 to an appropriate thickness such as

  0.25 mm in the vicinity of fasteners 25 and 26 of

  current. Aluminum easily forms aluminum oxide with either water vapor or free oxygen and therefore is a convenient reagent for extracting or trapping free oxygen and water vapor from the atmosphere

of the lamp.

  On the other hand, zirconium reacts with the oxygen of hydrogen, not by forming an oxide coating on its surface, but by surface adsorption of gases with

  migration or subsequent absorption of gases in the

  zirconium cules. As a result, zirconium is a long-lived or continuous getter that continually cleans

  the atmosphere of the lamp during its operation.

  In a preferred embodiment, particles or flakes of aluminum and zirconium are mixed in a binder such as amyl acetate and nitrocellulose and a getter material is formed which is then applied.

  at the current inputs in the vicinity of the attachments of the

  is lying. The application of the getter is done before the seal

  mounting of the lamp in the bulb and, consequently,

  the suspension and binding materials (amyl acetate and nitrocellulose) are sufficiently dissipated

  so that they do not contribute to the contamination of the

mosphere of the lamp.

  As indicated above, aluminum and zirconium

  nium trap impurities in the lamp, and

  see sufficient quantities of each of them to counter

  swing the oxide formed on the current inlets

  13 and 14 where they come out of the pinch 22 and

  very impurities in the lamp. We mix the

  metal particles from the getter with approximate

  equal amounts of nitrocellulose binder and amyl acetate support and form a suspension of the particles

  metal in a slurry that is applied to

  trés de courant for example by painting or tapping.

  In a slurry of amyl acetate and nitrocellulose, increasing the weight percent of aluminum makes the slurry more viscous and more adherent to the current entrances. The relative weight percent of aluminum and zirconium covers a wide range, especially since a greater amount of getter material can be applied

  these current inputs to compensate for small

  weight percentages. It is recommended that zirconium be the

  predominant material in weight and particular achievements

  containing weight percentages of aluminum

  in the range of 15 to 25% have been found to be satisfactory.

  Another particular achievement involved, in percent

  by weight, 18% aluminum and 82% zirconium.

  Although the present invention has been described in connection with

  with a standard gas-filled incandescent lamp, it is obvious that non-metallic copper current inputs can be used in combination with

  aluminum-zirconium getter in different types and

  figurations of lamps. In particular, we can use

  non-metallized copper current inputs in infrared lamps or lamps that use

  arc in combination with an incandescent filament.

  The combination of non-copper current inputs

  metallic and aluminum-zirconium getter of the invention

  provide many benefits. The present invention

  allows the use of non-metallic copper current

  rigidized and less expensive without affecting the life or

the quality of the lamp.

Claims (5)

R E V E N D I C A T IO N S   1. An incandescent lamp comprising a glass bulb (11) hermetically sealed with a filament (12) electrically connected to and mechanically supported by a set of current inputs (13, 14) which pass uniformly through a glass foot ( 15), characterized in that at least one of the current inputs is made of unmetallized copper onto which an aluminum getter is applied. and zirconium (30).   2. Lamp according to claim 1, characterized in that the current inputs are copper reinforced by   non-metallized dispersion or dispersion-reinforced copper   non-sheathed and non-metallized.   3. Lamp according to claim 1, characterized in   the aluminum and zirconium getter (30) is   in the vicinity of fasteners (25, 26) of the current inputs (13, 14).   4. Lamp according to claim 1, characterized in that the aluminum and zirconium getter consists of aluminum and zirconium particles in relative weight percentages of about 18% and 82% respectively, which are combined in a binder. nitrocellulose and a carrier of amyl acetate.   5. Lamp according to claim 1, characterized in that the getter of aluminum and zirconium has a thickness about 25 microns.