EP0446460B1 - Halogen incandescent lamp having a single pinch - Google Patents

Abstract

Instead of a frame, a halogen incandescent lamp (1) has one or more glass webs (20, 21) as coil holders, which are constructed from the material of the bulb (2). The luminaire body (15) is fused in between the web halves. <IMAGE>

Description

The application is closely related to the three parallel applications Nos. EP-A-0 446 458, EP-A-446 459 and EP-A-0 446 461.

The invention relates to a halogen incandescent lamp pinched on one side according to the preamble of claim 1.

From SU-A-1 112 442 a halogen incandescent lamp pinched on one side is known, in which a glass tube, which is arranged in the lamp axis, holds a U-shaped filament. The tube is not formed from the piston material, but separately. It protrudes freely from the pump nozzle into the inside of the piston and holds the helix mechanically by means of a hole in the tube.

Another halogen incandescent lamp, which also dispenses with a quartz beam, is known from EP-OS 173 995. The filament is only held by a frame wire that is melted into the pinch. If this lamp is designed for direct operation at mains voltage, the filament used for this must have a relatively high resistance and consequently a long length. For this reason, the luminous body is bent into two luminous arms and has an overall V-like or U-like shape.

It has been shown in the company that this concept, which is promising in itself, is linked to two major disadvantages. On the one hand, these lamps show a high sensitivity to vibrations. If the burning lamp is subjected to impact, the both arms of the filament come into contact and the filament sections which are still energized burn out due to overload. This is caused by the fact that the full mains voltage is only present at a fraction (generally half) of the wire length.

On the other hand, in a horizontal burning position, the lamp arms can come into contact with the inner wall of the bulb, since the free length of the arms is relatively large and a certain spiral sag (approx. 10%) cannot be avoided. Ultimately, this will accelerate the blackening and shorten the lifespan.

It is an object of the invention to provide a halogen lamp which is squeezed on one side and has a long service life, which can be produced in a particularly simple and cost-saving manner and is particularly easy to automate.

This object of the invention is achieved by the characterizing features of claim 1. Particularly advantageous designs can be found in the subclaims.

When looking for a particularly simple concept for the construction of a lamp that is squeezed on one side, it is obvious to try to further simplify the frame and thus make it more automation-friendly. The present invention now represents a decisive breakthrough that aims in a completely different direction. Instead of simply changing the frame, it is completely dispensed with. Do his job now glass webs formed from the material of the piston wall. Initial attempts to use separate glass webs inserted into the flask failed. It has been found that these holding bars do not withstand the high temperature loads, which is why the desired long service life (2000 hours) has not been achieved.

Surprisingly, it has been shown that glass webs, which are formed from the material of the bulb, have a much higher temperature resistance. The reason is that with this technology there is additional cooling from the outside and heat dissipation to the outside and therefore the decomposition of the glass web is prevented.

The filament consists of two straight legs and a connecting part, so that it is bent in a U-shape or V-shape. However, it can also have more than two legs.

In the area of the connecting part between the two legs, it is fixed by a glass web, which holds the luminous element mechanically or by means of a pinch. In addition, further glass webs can also be arranged along the two legs, which serve either as a fixing pinch or as a mechanical separation aid between the two legs. The particularly intimate connection due to the pinching leads to excellent heat dissipation at this helix point, which prevents blackening and devitrification of the glass web and also leads to the fact that the pinched helical area practically no longer shines.

In terms of its function, either the entire luminous element lights up or it is divided into individual luminous sections, with non-luminous (i.e. actually weaker luminous) connecting sections between them. A non-luminous connecting section in this sense can in particular be the curved connecting part.

In principle, the web can be solid (as a rod), but this is not completely satisfactory in terms of production technology and cooling. The web is preferably of tubular design with a circular or oval cross section (i.e. as a longer furrow). This improves the cooling, since the heat-emitting surface is larger than the heat-radiating coil part. An ideal operating behavior, even with a horizontal burning position, can be achieved if several glass webs are used, which are suitably distributed along the luminous element.

Two basic alternatives to the holding effect of the webs are possible. The first option is a mechanical bracket, e.g. the tube-like webs lie tight against the filament. Another variant is that the webs thread a turn of the filament, so to speak. The pitch of the secondary helix in the region of the web is advantageously chosen to be so large that it is adapted to the outside diameter of the web. This technique is described in more detail in parallel application no. ... (GR 90P5510).

In the second option, the tubular one fixes Bridge the filament in that a piece of the filament is squeezed between two web halves. The essential point in this connection is that the temperature of the glass web does not exceed a certain limit, because otherwise stresses occur or even the glass web softens. In the case of quartz glass, this limit temperature is around 800-900 ° C, while for tempered glass a temperature of around 600 ° C becomes critical. In the area of the pinching, the web thickness advantageously exceeds the external dimensions of the luminous element by at least 100%.

Another possible application for such webs is that of a release agent between two parallel legs of the filament.

At low temperatures in the lamp (generally corresponding to low power, for example 50 W), a continuously double-coiled filament can be squeezed into the glass webs. At medium temperatures in the lamp (generally corresponding to medium power, for example 75-150 W), a double-coiled filament can be equipped with single-coiled and therefore cooler sections, which in turn are melted into the glass webs. At high temperatures in the lamp (generally corresponding to powers over 150 W), it is finally advantageous to provide the double-coiled filament with uncoiled sections that have a considerably lower temperature. Additional cooling is possible using core pins that short-circuit the filament in the area of the webs, so that its temperature is lowered sharply.

These considerations apply accordingly to single-filament lamps.

These reduced temperature sections also prevent increased blackening and devitrification, which could lead to early failures. In general, the power density in these sections is significantly reduced. Conversely, as the person skilled in the art knows, the heat losses are lowest with double coiling.

This technology creates an extremely simplified mounting of the filament and is very easy to manufacture. In addition, the dimensions of the glass webs are chosen so that there is no significant impediment to the halogen cycle in the lamp bulb. The inside diameter of the webs is typically 0.5 mm near the axis.

Because the tubular webs are widened in a funnel shape, there are no excessively thin spots in the region of the transition to the piston wall, which would reduce the bursting pressure. The wall thickness remains fairly homogeneous.

The webs are manufactured before the piston end is squeezed. The filament is clamped by means of an interchangeable holder and inserted into the bulb, which is open on one side. The lamp bulb is heated in the area of the future webs with burners and shaped by means of stamps, which are opposite each other. This technique has the great advantage that the position of the filament can no longer be subsequently adjusted by this process. Each web can be produced particularly easily by the two stamps, which are designed as conically tapering round rods, pressing two hollow, in particular funnel-shaped "glass fingers" into the bulb wall, which finally touch in the lamp axis (or in its vicinity). The diameter of the funnel on the bulb wall and the degree of narrowing towards the lamp axis depend on the size of the heating zone on the bulb wall. The absolute value of the glass tube diameter near the axis depends on the dimensions of the stamp. In the area of the interface between the two "glass fingers", a stopper on which the seam between the two stopper halves can still be recognized is advantageously left, which considerably simplifies production. In the case of the squeezing technique, the filament lies exactly between the two "glass fingers" and is fixed to form the stopper. In the case of the production of the furrow-like glass webs, the stamps have an oval or rectangular profile.

Overall, a halogen incandescent lamp with a long service life (2000 hours) is presented, which is extremely shockproof and is suitable for simple construction with few components. This also means that the overall length can be reduced by approx. 30% in comparison to standardized halogen incandescent lamps, since the frame structures in the vicinity of the pump stem are eliminated. As a side effect, additional savings in filling quantities occur due to the smaller piston volume. The pipe diameter can be reduced by approx. 20%.

In general, the larger the internal dimension of the piston to be bridged, the greater the difference in wall thickness in the tubular glass web. A lamp that is particularly well adapted to the glass web technology is characterized by a bulb with an oval or the like. Cross section from. The "bridging" for the webs takes place in the direction of the short semi-axis, so that the wall thickness of the glass webs does not decrease too much towards the lamp axis and therefore remains fairly homogeneous.

The lamps according to the invention are suitable for direct operation at mains voltage, which should be understood to mean a range from approximately 80 V to 250 V. Typical wattages are 15 to 200 W. These lamps are used, for example, for general lighting purposes.

The invention is primarily suitable for the mounting of luminous bodies with two legs. However, this does not exclude the use for differently designed lamps, e.g. with four legs.

Figur 1

ein erstes Ausführungsbeispiel einer Halogenglühlampe in Seitenansicht mit einem Glassteg und einem unterbrochen gewendelten Leuchtkörper

Figur 2

ein zweites Ausführungsbeispiel einer Halogenglühlampe mit mehreren Glasstegen unter Benutzung eines Furchenstegs in zwei Seitenansichten, jeweils um 90° gedreht

Figur 3

alternative Ausführungen für ein Detail aus Figur 2b in Vergrößerung (Fig. 3a und 3b)

Figur 4

ein Detail aus Fig. 2b im Querschnitt (Fig. 4a) sowie eine alternative Ausführung (Fig. 4b)

Figur 5

ein weiteres Ausführungsbeispiel in Seitenansicht unter Verwendung mehrerer Glasstege und eines durchgehend gewendelten Leuchtkörpers

The invention is explained in more detail below with the aid of several exemplary embodiments. It shows schematically

Figure 1

a first embodiment of a halogen incandescent lamp in side view with a glass web and an interrupted filament

Figure 2

a second embodiment of a halogen lamp with several glass webs using a furrow bar in two side views, each rotated by 90 °

Figure 3

alternative versions for a detail from FIG. 2b on an enlarged scale (FIGS. 3a and 3b)

Figure 4

a detail from Fig. 2b in cross section (Fig. 4a) and an alternative embodiment (Fig. 4b)

Figure 5

a further embodiment in side view using several glass webs and a continuously coiled filament

FIG. 1 shows a halogen incandescent lamp 1 for general lighting purposes with a power of 200 W, which is preferably suitable for direct connection to the 110 V network. It has a cylindrical piston 2 made of quartz glass with an outer diameter of approximately 12.5 mm with an inner diameter of 10.5 mm (with a tolerance of 0.8 mm) and a total length of approximately 35 mm. One end of the piston 2 is shaped into a dome 3 which has a pump tip 4 in the center. The other end of the piston is closed with a pinch seal 5. The flask with a volume of 1.65 cm³ is filled with an inert gas mixture of 80% Kr and 20% N₂, to which a halogen addition of 0.005% CBrClF₂ is added.

A V-shaped lamp body 6, which is double coiled, extends over almost the entire inner length of the bulb volume, the connecting part 7 of the V, which is rounded, in the Arranged near the dome 3, while the two straight legs 8 of the V, which form the actually luminous, about 15 mm long filament arms, extend from the connecting part 7 to the pinch seal 5 and thereby to the pinch seal 5 slightly outward from the lamp axis to open. While the two legs 8 are double coiled, the connecting part 7 is uncoiled (or simply coiled). The luminous element 6 is mechanically held by a glass web 9 which bears against the inside of the rounded part 7. The web 9 is a glass tube which is formed from the material of the bulb and which extends transversely to the lamp axis and to the plane of the luminous element over the inside diameter of the bulb. The glass tube 9 has a diameter of approximately 1.2 mm near the axis and widens toward the piston wall 2 'on both sides in the manner of a funnel 10 to approximately twice (or even four times) the diameter. A plug 11 is left in the tube in the region of the lamp axis.

The two luminous limbs 8 merge at their pinch-side ends into short, simply coiled sections which act as power supply lines 12. The luminous element 6 is tensioned in the bulb 2 in that the current leads 12 are melted into the pinch seal 5 and are welded there to sealing foils 13. The power supply lines 12 with a total length of approx. 6 mm protrude from the pinch seal 5 approx. 1 - 2 mm into the piston volume, which is why the usual core pins can advantageously be dispensed with. At the outer end of the films 13 contact pins 14 are welded, which protrude beyond the end of the pinch seal 5 to the outside.

A second exemplary embodiment, the structure of which essentially corresponds to the first exemplary embodiment, is shown in FIG. It is a 220 V halogen incandescent lamp with a power of 100 W. The luminous element 15 is now bent in a U-shape. The two legs 8 'of the U, which run parallel to the lamp axis, are in turn subdivided into two luminous, double-coiled sections 16, which are each connected to one another by a single-coiled section 17. The connecting part 18 of the U is also simply coiled. It is arranged transversely to the lamp axis in the vicinity of the pump tip 4, two short brackets 19 being angled through 90 ° and each extending to a section 16.

At the level of the connecting part 18, the luminous element 15 is fixed by an oval glass web, the two halves of which are designed as longitudinal furrows 20. They extend over most of the length of the connecting part 18, so that it is squeezed between the two longitudinal furrows 20. In addition, the luminous element 15 is fixed in the region of the simply coiled sections 17 by a further glass web. It is a tube 21 with a circular cross-section which - like the oval tube - narrows increasingly like a funnel starting from the piston wall towards the center of the piston. At the level of the luminous element, a stopper 22 is left in the tube, into which the simply coiled section 17 is squeezed in the middle. This holding technique is particularly suitable as an alternative to the mechanical holder described in the first embodiment when using a single glass tube.

Another variant of this squeezing technique is shown in FIG. 3a. Starting from the funnel-shaped extension 23 on the bulb wall, the glass web narrows to a tube 21 of constant diameter, the central stopper 22 of which squeezes the luminous element section 17. The plug has the shape of a solid cylinder. In order to achieve an improved cooling in the area of the single-helix connection section 17, the helix of the connection section 17 can be short-circuited by a core pin 36. This technique is also particularly suitable for mechanically retaining webs, since effective cooling is particularly desirable here.

An alternative embodiment (FIG. 3b) uses a tube 24 which narrows from the bulb wall in a funnel shape towards the center of the lamp, the inner walls of which converge and thus form the plug region 25 into which the section 17 of the luminous element is squeezed.

FIG. 4a shows a schematic cross section through the lamp according to FIG. 2 at the level of the two funnel-shaped glass tubes 21, which fix the two sections 17 by being pinched.

For the effectiveness of the pinching, it is sufficient if the two web halves in the area of the stopper 22 only have a common seam 37 without being homogeneously fused to one another (FIG. 4b). This can be used advantageously in all of the exemplary embodiments described here.

In the case of lamps with a relatively large bulb diameter, a flattened, e.g. oval or elliptical, cross section of the piston 2˝ used (Fig. 4b). The volume of the piston 2˝ need not change compared to a cylindrical piston 2. In contrast, the semi-axis advantageously shortens in the direction of the glass webs, while the semi-axis extends transversely to the glass webs. In this way, a greater wall thickness of the glass tubes can be achieved compared to a cylindrical piston with the same volume.

Another exemplary embodiment is finally shown in FIG. 5. It is a halogen incandescent lamp with an output of 50 W. The luminous element 26 is continuously coiled and bent in a U-shape. The fixation is carried out by two glass tubes 27. They squeeze the luminous element in the region of the two 90 ° bends between the legs 28 and the connecting part 29. However, the diameter of these webs is significantly larger (approx. Factor 1.4) than if a straight section of the filament was squeezed to fully enclose the 90 ° bend. Alternatively, the two glass tubes 27 can also be attached to the transverse connecting part 29 without including the 90 ° bends.

In general, the diameter of a glass web (or its height in the case of the furrow-like glass web) should be at least twice as large as the diameter of the lamp body area to be squeezed in order to ensure secure fixation.

In the case of the 50 W lamp, an additional separating web 30 is also arranged approximately centrally in the lamp bulb, so that it extends at the level of the center of the leg between the two legs 28 and transversely to them. The separating web prevents the two relatively long legs 28 from being knocked together. The use of a dividing web 30 (or more) is always advantageous if one wants to avoid direct fixation of the filament legs or also the provision of single or uncoiled filament portions in the area of the otherwise doubly coiled Thigh is undesirable. This separating web 30 is also designed as a funnel-shaped glass tube.

Core pins 36 at the level of the separating web 30 are also suitable here for premature blackening or the like. to prevent.

Due to their increased compactification, such lamps are particularly well suited for installation in an outer bulb.

In FIG. 6, the halogen incandescent lamp of FIG. 5 described so far is mounted in an outer bulb 31 as an example. The possibly two-part power supply lines 32 are squeezed into a plate foot 33, which is melted into the neck 34 of the evacuated outer bulb 31. The outer bulb 31 carries a screw base 35.

The invention is not restricted to the exemplary embodiments shown. The individual features of different exemplary embodiments can be combined with one another. It is particularly suitable the invention also for halogen incandescent lamps for mains operation at 110 V. Furthermore, the two legs of the filament can be subdivided again. The filling can also consist of other components known per se, for example CH₂Br₂ can be used as a halogen additive. Hard glass is also suitable as the bulb material, the luminous element being provided with external contact pins or the like via solid current leads known per se, which are melted directly into the pinch seal. connected is. The decision as to which type of glass webs is used in which number depends on the one hand on the temperature conditions and on the other hand on the free length of the lamp body sections and the shape of the lamp body. An indication of the free length is the voltage drop that occurs there. It should not exceed approx. 60 V.

The number of glass webs varies in particular depending on the power level of the lamp and the length of the filament and its stability with regard to sagging. For stiff lamps with high performance may be sufficient already a glass walkway. Under certain circumstances, more than three glass webs can be used for less stiff lamps with low power.

The invention provides an inexpensive halogen incandescent lamp with low power consumption down to 15 W for direct mains connection, as is of particular interest for general lighting.

Claims (14)

1. Halogen lamp (1), pinched at one end, for operating from mains voltage, comprising
   a hermetically sealed bulb (2) made from transparent material, which defines a longitudinal axis,
   a filling of inert gas and a halogen-containing admixture,
   a luminous element (6; 15; 26) having at least two limbs and a connecting part, in particular a V-shaped or U-shaped luminous element,
   a glass web (9) which holds the luminous element (6; 15; 26) in the region of the connecting part (7) and
   a power supply system which is connected to the two limb ends of the luminous element,
   characterized in that the luminous element (6; 15; 26) is held exclusively by one or more webs (9; 20; 21; 27; 30) which are formed from the material of the bulb and extend essentially transverse to the longitudinal axis respectively between two points of the bulb side walls which are approximately opposite one another.
2. Halogen lamp according to Claim 1, characterized in that the luminous element (6; 15; 26) defines a plane, the webs (9; 20; 21; 27; 30) extending transverse to the longitudinal axis and to the plane of the luminous element.
3. Halogen lamp according to Claim 1, characterized in that at least one first glass web (9) is used which holds the luminous element in the region of the connecting part (7).
4. Halogen lamp according to Claim 3, characterized in that at least two further glass webs (21) fix the luminous element in the region of the limb (8′).
5. Halogen lamp according to Claim 1, characterized in that the luminous element (15; 26) is pinched at least at one part of the webs (20; 21; 27).
6. Halogen lamp according to Claim 1, characterized in that the luminous element (6) is held mechanically at least by one part of the webs (9).
7. Halogen lamp according to Claim 1, characterized in that the webs (9; 21; 27; 30) are of tubular shape.
8. Halogen lamp according to Claim 7, characterized in that the webs widen in the shape of a funnel towards the bulb wall.
9. Halogen lamp according to Claim 1, characterized in that the luminous element (15) is subdivided into a plurality of luminous sections (16) which are separated by one or more connecting section(s) (17), the luminous sections (16) being doubly spiralled and the connection section(s) (17) being singly spiralled or not being spiralled.
10. Halogen lamp according to Claim 9, characterized in that the webs (21) hold the luminous element (15) in the region of the connecting sections (17).
11. Halogen lamp according to Claim 3, characterized in that the luminous element (15) is bent in a U-shaped fashion and the web (20) which holds the luminous element (15) in the region of the connecting part (17) has an oval cross-section.
12. Halogen lamp according to Claim 1, characterized in that the bulb is a tube having a circular or flattened cross-section, the webs extending parallel to the shorter transverse axis in the latter case.
13. Halogen lamp according to Claim 1, characterized in that the helical sections (17) adjacent to a glass web (21; 30) are equipped with a core pin (36) for better cooling.
14. Method for producing a halogen lamp according to Claim 1, characterized in that each web is formed by providing that after the insertion of the luminous element the lamp bulb, which is open at one end, is heated in a punctiform fashion using two burners, which are opposite one another, and is pressed in using two plungers.

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