US3743375A

US3743375A - Halogen filament lamp

Info

Publication number: US3743375A
Application number: US00126552A
Authority: US
Inventors: Fraeye D De
Original assignee: US Philips Corp
Current assignee: US Philips Corp
Priority date: 1970-04-04
Filing date: 1971-03-22
Publication date: 1973-07-03
Anticipated expiration: 1990-07-03
Also published as: NL7004872A; FR2094952A5; BE765246A; GB1334453A; DE2111692A1

Abstract

A method of manufacturing a halogen filament lamp in which a wire supporting the filament of the lamp is used having a meltable metal portion. The meltable metal portion is oriented approximately opposite to the sealing foil and the metal portion melts away during the formation of the pinch seal. The method provided a capability of permanently supporting the filament even during the pinching operation.

Description

United States Patent 1191 [111 3,743,375 De Fraeye July 3, 1973 HALOGEN FILAMENT LAMP [56] References Cited [75] Inventor: Dirk Jules Reml De Fraeye, UNITED STATES PATENTS Emmasmgel, Emdhoven 3,408,719 11/1968 Van Sickler et al 29/2s.1s Netherlands 3,600,053 8/1971 Smith 316/19 73 Assignee: U.S. Philips Corporation, New York,

N,Y, Primary ExaminerCharles W. Lanham Assistant Examiner-J. W. Davie [22] 1971 Attorney-Frank R. Trifari [21] Appl. No.1 126,552

- [57] ABSTRACT [30] Foreign Application Priority Data 1 A method of manufacturing a halogen filament lamp in Apr. 4, 1970 Netherlands 7004872 hi h a wire su orting the filament of the lamp is used having a meltable metal portion. The meltable metal Cl 9/25.l5, 313/235, portion is oriented approximately opposite to the seal- 313/315 ing foil and the metal portion melts away during the [5 l 1 Int. Cl. H01] 9/38 formation of the pinch seal, The method provided 3 C8- [58] Field of Search 316/18, 19, 20;

pability of permanently supporting the filament even during the pinching operation.

5 Claims, 5 Drawing Figures PATENTEUJIIL 3 1975 Fig.5

INVEN'IOR. DIRK J.R. DE FRAEYE AGENT HALOGEN FILAMENT LAMP The invention relates to a method of manufacturing a tubular halogen filament lamp which comprises a tubular lamp vessel closed by at least one pinch seal, in the longitudinal direction of which vessel is arranged a filament which is connected to at least one lead-in member incorporated in the pinch seal, said filament being supported in at least one place by a part of a supporting wire likewise extending in the longitudinal direction of the lamp and embedded in the pinch seal. Such a method is known from German Utility Model 6,753,344.

The parallel arrangement inside a tubular lamp vessel of an elongated filament and a wire supporting the filament is rather difficult considering that the supporting wire must have a shorter length than such a filament which is also provided with connecting foils and lead-in conductors. Actually, it is undesirable to lead the supporting wire directly through the pinch seal to the exterior; such a lamp has no gas-tight pinch seal. In the manufacture of such lamps, it is therefore always difficult to cause the supporting wire to assume the pre scribed position relative to the filament during the pinching operation. On the contrary, the filament itself will often serve as a support of the supporting wire during the pinching operation.

It is the object of the invention to provide a method which orients the supporting wire during the formation of the pinch seal in a precise prescribed position relative to the filament.

The method according to the invention is characteri zed in that the starting material is an assembly formed by the filament having secured thereto lead-in members and a wire supporting said filament in at least one place, a part of said wire being formed by a metal member which is meltable only during the pinching operation, said assembly being surrounded by a glass tubular member, the pinch seal being formed in said tubular member while embedding the lead-in members and the meltable metal members, the resulting lamp vessel being then provided with a suitable gas filling and being sealed. By the introduction of a few metal members which are not meltable until during the pinching operation, it becomes possible to have a supporting wire which, unlike in the known method, is not shorter but longer than the length of the filament having the lead-in conductors secured thereto. This enables the positioningof the supporting wire together with the lead-in conductor connected to the filament so that the position of the supporting wire is fixed upto substantially the instant at which the appropriate squeezing members have completed their pinching operation to form the pinch seal in the lamp vessel. Only at that instant does the interposed metal member melt away. It has been found that the desirable position of the supporting wire assumed just prior to the sealing and pinching operation is not influenced substantially. In the finished product, this melted member remains an electrically insulated metal mass embedded in the pinch seal.

Preferably a meltable metal member is used which is in the form of a tube in the two ends of which spaced parts of the supporting wire are secured. It has been found that this construction in which the tube is preferably manufactured from nickel, is to be preferred over a solid rod as a metal member.

The invention is particularly suitable for use in a method of manufacturing a tubular halogen filament lamp which comprises a tubular lamp vessel sealed at either end by a pinch seal, in the longitudinal direction of which a filament is arranged which is connected to foils embedded in the pinch seals, which foils are each connected to a lead-in conductor emerging from the lamp, said filament being supported in at least one place by a supporting wire likewise extending in the longitudinal direction of the lamp, said wire being likewise embedded at either end in the two pinch seals.

This method is characterized in that the starting material consists of two parallel chains, one of which is formed by the filament having foils connected thereto, to which foils are connected lead-in conductors, and the other is formed by a wire supporting the filament in at least one place and a part of which, which is present approximately at the height of each foil, is formed by a metal member which is not meltable until during the pinching operation, said two chains being surrounded by a tubular glass member which is shorter than the length of each chain, pinch seals being formed at either end of said tubular member while embedding the foils and the meltable metal members, the resulting lamp vessel then being evacuated through a lateral exhaust tube, provided with a suitable gas filling, after which said exhaust tube is sealed. So for the manufacture of the lamp two parallel chains are used which can be held collectively in a particularly simple manner during the pinching operation.

According to a preferred embodiment of this method, the two chains may be united by bridge members to form a single coherent assembly. The resulting chain may then be closed entirely by using two bridge members. By using such a coherent chain, the handling during the pinching operation becomes particularly simple. In that case it is sufficient for the composite chain to be held by its two bridge members, the chain maintaining its coherence substantially up to the instant at which the squeezing members have completed their action. If desirable after the formation of the pinch seal, a separation operation may be carried out on the bridge member formed outside the pinch seal, which bridge member is secured in said pinch seal at either end. In that case the bridge member serves as a lead in conductor which is secured to the filament member via a sealing foil.

In order that the invention may be readily carried into effect, it will now be described in greater detail, by way of example, with reference to the accompanying drawing, in which FIG. 1 shows a two-pinch halogen filament lamp to be manufactured.

FIG. 2 relates to a method according to the invention,

FIG. 3 shows on an enlarged scale a part of the supporting wire shown in FIG. 2,

FIG. 4 shows a filament lamp obtained by the method according to the invention, and

FIG. 5 shows a mono-pinch halogen filament lamp.

FIG. 1 shows an electric filament lamp which comprises a tubular lamp vessel 1 of quartz glass. At its end said lamp

vessel comprisespinch seals

3 and 5. A coiled coil filament 7 of tungsten wire is arranged inside the lamp. The ends of the filament 7 are secured to sealing foils 9 and ll of molybdenum. External conductors l3 and 15 are secured to said foils.

The filament 7 is supported in known manner by a loop 17 formed in a supporting wire 19 of molybdenum and extending parallel to the filament 7, and the ends of which are embedded in the

pinch seals

3 and 5. The filament lamp shown is provided with a suitable halogen-containing gas filling in a manner conventionally used for halogen filament lamps.

According to the invention, starting material for the manufacture of a filament lamp shown in FIG. 1 is an assembly as shown in FIG. 2. This assembly comprises the components already described with reference to FIG. 1, which are arranged as two parallel chains inside a tubular member 23 of quartz glass which is open at either end, in the manner as shown in FIG. 2. In FIG. 2, said tubular member is shown in broken lines. The first chain comprises the filament 7,

foils

9 and 11, and

external conductors

13 and 15. The second chain is constituted by the supporting wire 19,

metal member

25 and 27 secured thereto, and supporting

wires

29 and 31 which are secured thereto and have the same thickness as the wire 19 and likewise consist of molybdenum. The

metal members

25 and 27 are chosen to consist of such a material that they melt only when the operation of the squeezing members to form the pinch seals 3 and is carried out. These members are manufactured, for example, from nickel and are in the form of tubes. FIG. 3 shows the tube 27 on an enlarged scale. The ends of supporting

wires

19 and 31 are secured in said tube 27.

During the pinching operation which is performed subsequently to form the

pinch seals

3 and 5, the assembly comprising the two chains are held by suitably constructed

holders

33 and 35 shown in broken lines. In these holders the conductors l3 and 15 and the supporting

wires

29 and 31 are held in a prescribed position. The loop-shaped part 17 of the supporting wire 19 can continue to support the filament 7 during the performance of the pinching operations.

During the formation of the

pinch seals

3 and 5, the ends of the tubular member 23 which are softened by heating are squeezed between two squeezing blocks not to be described in detail. Just before the quartz glass contacts the

members

25 and 27, the

members

25 and 27 will melt during which time the position of the supporting wire 19 does not vary to any substantial degree. This lamp vessel is then evacuated, provided with a suitable gas filling, and the exhaust tube 21 is sealed.

The resulting product is shown in FIG. 4. In this Figure the melted

metal members

25 and 27 form insulated embedded

masses

37 and 39, respectively. Viewed from the supporting wire 19, they are embedded in the elongation of the ends of the wire in the pinch seals 3 and 5 in an electrically insulted manner between the

wire parts

19 and 29 and 19 and 31, respectively.

In the above embodiments, the starting material was constituted by two separate parallel chains. It will be obvious that it is also possible to use a single closed chain having two parallel branches connected by

bridge members

41 and 43 as they are shown in broken lines in FIG. 4. Such a closed chain has the advantage of forming a rigid cohering assembly up to the formation of the pinch seals. In that case, the

extra bridge members

41 and 43 may be formed by bending back the

parts

29 and 31 of the supporting wires and connecting them to the

foils

9 and 11. The parts of the wire present outside the pinch seals 3 and 5 are then each incorporated with their two ends in the pinch seals in an insulated manner and may serve as external connection members. If desirable, a separation operation may be carried out along the

broken lines

45 and 47.

The invention has been described with reference to an embodiment for a filament lamp having two pinch seals. Of course it is equally suitable for use in a filament lamp having only one pinch seal (see FIG. 5). The lamp shown in FIG. 5 also shows a filament 51 which is supported by means of a central supporting member 53. This central supporting member in this case also has a meltable part which melts away only during the formation of the pinch seal. FIG. 5 illustrates the resultant pinch after the melting has occurred. Again the presence of an embedded mass 55 is to be noted.

What is claimed is:

l. A method of manufacturing a tubular halogen filament lamp of the type having a tubular lamp vessel sealed by at least one pinch seal, said vessel having a longitudinal filament connected to at least one lead-in member which is incorporated in the pinch seal, the filament being supported in at least one place by a supporting wire which wire is embedded in the pinch seal and extending longitudinally in the lamp comprising the steps of:

arranging as an assembly an elongated filament having at least one lead-in member attached thereto and a supporting wire, said supporting wire positioned to be substantially parallel to the longitudinal axis of the tube and supporting the filament in at least one place, said wire having a portion including a member meltable during the pinching operation;

surrounding said assembly by an elongated glass tubular member;

pinching at least one end of said member by applying pressure and heat so as to simultaneously melt said wire member and form a pinch seal for said lamp; evacuating said lamp;

filling said lamp with an appropriate gas atmosphere;

and sealing said lamp. 2. A method of manufacturing a tubular halogen filament lamp of the type which is sealed at either end by a pinch seal and has a longitudinal filament connected to foils embedded in the pinch seal, which foils are each connected to a lead-in conductor which emerges from the lamp, the filament being supported in at least one place by a part of a supporting wire which similarly extends longitudinally within said lamp, said wire also being embedded at either end, said method comprising the steps of:

coupling a first chain of elements including a filament, foils secured to either end of said filament, and lead-in conductors secured to said foils;

coupling a second chain of elements and orienting it substantially parallel to said first chain, said second chain including a wire supporting said filament in at least one place and a pair of meltable metal members positioned approximately opposite said foils; surrounding said two chains by a tubular glass memher which is shorter than the length of each chain;

forming pinch seals at either end of said tubular member, thereby embedding the foils and melting and embedding the meltable members in said pinch seals;

evacuating said resulting lamp vessels through a lateral exhaust tube;

5. A method as claimed in claim 2, wherein the starting material is a supporting wire of which at least one of the ends is bent back and secured to one of the foils,

in which after the formation of the pinch seal a separation operation may be carried out on the bent'part of the supporting wire extending from the lamp vessel.

Claims

2. A method of manufacturing a tubular halogen filament lamp of the type which is sealed at either end by a pinch seal and has a longitudinal filament connected to foils embedded in the pinch seal, which foils are each connected to a lead-in conductor which emerges from the lamp, the filament being supported in at least one place by a part of a supporting wire which similarly extends longitudinally within said lamp, said wire also being embedded at either end, said method comprising the steps of: coupling a first chain of elements including a filament, foils secured to either end of said filament, and lead-in conductors secured to said foils; coupling a second chain of elements and orienting it substantially parallel to said first chain, said second chain including a wire supporting said filament in at least one place and a pair of meltable metal members positioned approximately opposite said foils; surrounding said two chains by a tubular glass member which is shorter than the length of each chain; forming pinch seals at either end of said tubular member, thereby embedding the foils and melting and embedding the meltable members in said pinch seals; evacuating said resulting lamp vessels through a lateral exhaust tube; filling said lamp with an appropriate gas; and sealing said lamp.
3. A method as claimed in claim 1, wherein the meltable metal member is in the form of a tube in the two ends of which parts of the supporting wire are secured at some distance from each other.
4. A method as claimed in claim 3, wherein the metal member is in the form of a nickel tube.
5. A method as claimed in claim 2, wherein the starting material is a supporting wire of which at least one of the ends is bent back and secured to one of the foils, in which after the formation of the pinch seal a separation operation may be carried out on the bent part of the supporting wire extending from the lamp vessel.