EP0800202A2 - Optical radiators - Google Patents

Abstract

The lamp is based on a fluorescent discharge tube (14) made from quartz glass and bent to form two parallel limbs joined by a U-bend (15) with 1.5 mm thick wall and an outer diameter of 9 mm. The limbs themselves are 1 mm thick and 15 mm in diameter. Electrode connections (21) are brought out through two pinches (18,19), about 20 mm long and 2.5 mm thick, cemented into a ceramic base (20). The plane of the pinches intersects that of the curvature at an angle slightly less than or equal to 90 deg.

Description

The invention relates to an optical radiator with a light tube bent in a plane of curvature, the ends of which are each closed by means of a pinch formed flat in a pinch plane, through which at least one electrical connection is guided from the outside into the light tube.

Such an optical emitter is known from the product information brochure "UV-C high-performance emitters; disinfection with maximum efficiency" from Heraeus Noblelight GmbH from 1994 (printed notice: 2C 7.94 / N T&D). The UV high-power radiator described therein consists of a U-shaped discharge tube, the ends of which are each sealed gas-tight by means of a pinch and which are embedded in and held in a common ceramic base. The electrical connections for electrodes arranged inside the discharge tube are guided from the outside through the squeezes. The plane of curvature runs parallel to a plane that intersects the central axes of the two free legs of the U-shaped radiator.

The bruises have an upper and a lower flat side. The pinch extends over a larger area and is essentially rectangular. The "squeeze plane" here is the plane that runs parallel to the two flat sides. It also runs parallel to the plane of curvature.

In the known high-performance radiator there is a risk of breakage in the area of the bruises, especially when the radiator is loaded in the direction perpendicular to the plane of curvature, for example due to its own weight.

To solve this problem, embodiments of optical radiators are known in which a metallic sleeve surrounds the bruises and which at the same time supports the light tube. Such a radiator is, for example, from the product information document "NARVA; Lichtprodukte "by the Gesellschaft für lichttechnischeproducts mbH (printed notice 06/1995). The metallic sleeve engages both the base and the tubular part of the light tube, so that mechanical stress on the pinch itself is avoided as much as possible. that the sleeve is firmly connected to the quartz glass tube. The assembly of the sleeve is relatively complex and requires great care.

The invention is therefore based on the object of specifying an optical radiator in which the risk of breakage in the area of the bruises is reduced and which is simple and inexpensive to produce.

Starting from the optical radiator mentioned at the outset, this object is achieved according to the invention in that the squish plane includes an angle in the range between 10 ° and 90 ° with the plane of curvature.

The optical tubes in the sense of this invention are bent in a plane of curvature. These are, for example, ring-shaped, oval or U-shaped fluorescent tubes. These light tubes are usually mounted so that the main radiation direction of the radiation emanating from them is perpendicular to the plane of curvature.

As explained at the beginning, the squeeze plane of the squeezes runs parallel to the plane of curvature in the known emitters. If these emitters are mounted in such a way that the main radiation direction is perpendicular to the plane of curvature, a force in the direction perpendicular to the squish plane acts on the bruises due to the weight of the emitter.

In contrast, the force due to the dead weight of the emitters acts in the same way according to the inventive emitters mounted in parallel or at an angle which is less than 90 ° to the crushing plane. The angle enclosed by the crush plane and the plane of curvature can deviate from a 90 ° angle. In this case, the squeeze plane runs obliquely to the plane of curvature. The value of the angle that the two planes enclose depends on the main direction of loading, that is the direction of the greatest expected mechanical loading of the light tube. It is the smallest angle that the two planes enclose with each other.

Because due to this alignment of the squeeze plane with respect to the main direction of load to be expected for the radiator, the surface resistance moment is the squeeze compared to the forces acting in the direction perpendicular to the plane of curvature. This applies equally to forces whose direction of action with respect to the plane of curvature describes an obtuse angle between 45 ° and 90 °. The risk of breakage with the bruises oriented in this way is therefore considerably reduced.

The area of the pinch is usually formed with a flat top and a flat bottom; the side edges of the pinch are provided with a perpendicularly projecting web. The specific design of the surface of the pinch does not play an important role for the radiator according to the invention. For example, the flat tops of the crush can also be concave or convex; or they can be provided with ridges or recesses. It is essential that the crushing plane runs in the angular range mentioned to the plane of curvature of the radiator.

The squeezing level is understood to be the level in the room in which the squeezing predominantly runs.

It is not necessary for the squeeze planes of the two squeezes to run parallel to one another, these can enclose an angle with one another, which should however not be greater than 120 °. This angle between the two crushing planes of the crushing can be open or closed at the bottom.

A spotlight in which the angle between the crushing plane and the plane of curvature lies in the range between 60 ° and 90 ° has proven particularly useful. Due to this orientation of the squeezes, a particularly high surface moment of resistance is generated in relation to a main direction of loading that is perpendicular to the plane of curvature. Such a radiator is therefore characterized by a particularly high breaking strength.

In a particularly suitable embodiment of the emitter, the crushing plane encloses an angle of 90 ° with the plane of curvature. Such an embodiment of the radiator is particularly easy to manufacture. It is particularly suitable for those emitters in which the bruises are mainly mechanically loaded in the direction perpendicular to the plane of curvature. This is regularly the case with those emitters in which the main emission direction is perpendicular to the plane of curvature and therefore parallel to the squeezing plane, so that the squeezing produces a particularly high surface resistance moment.

A spotlight in which the bruises are held in a common base has proven particularly useful. A common base for both crimped ends facilitates the assembly of the light tube. It is particularly advantageous if the squeeze planes of the respective squeezes run parallel to one another.

In a further preferred embodiment, the luminous tube is U-shaped. The two free legs of the U run parallel to each other and have the same length. In this radiator, the central axes of the two legs run parallel to the plane of curvature in the sense of this invention. U-shaped emitters are commercially available and are predominantly installed so that the main emission direction of the emitters is perpendicular to the plane of curvature. With such U-shaped emitters, the alignment of the squeeze plane according to the invention, as explained above, has proven particularly useful.

An embodiment of the radiator in which the light tube in a bend region of its bend, viewed in the direction of the light tube longitudinal axis, has a cross-sectional area that is smaller than the cross-sectional area from both sides of the bend area has also proven particularly effective with regard to a high breaking strength adjacent areas of the light tube.

The cross-sectional area is to be understood as the area in the direction of the longitudinal axis of the light tube, which is determined by the outer dimensions of the light tube in the respective area.

In the curvature area, the light tube has smaller external dimensions. This increases the flexibility of the light tube in this area. The risk of breakage, in particular in the case of bending stresses, such as occur during the manufacture of the radiator, but also during operation, is thereby considerably reduced. The area of curvature includes at least part of the bend; but it can also extend beyond.

Figur 1:

ein U-förmiges Entladungsrohr eines Hochleistungsstrahler nach dem Stand der Technik anhand einer technischen Zeichnung (teilweise im Schnitt) in einer Draufsicht in Richtung senkrecht zur Krümmungsebene,

Figur 2:

ein U-förmiges Entladungsrohr eines erfindungsgemäßen Hochleistungsstrahlers anhand einer technischen Zeichnung in einer Draufsicht in Richtung senkrecht zur Krümmungsebene, und

Figur 3:

eine Seitenansicht des in Figur 2 dargestellten Hochleistungsstrahlers in Richtung parallel zur Krümmungsebene (teilweise im Schnitt).

The invention is explained in more detail below on the basis of exemplary embodiments and the patent drawing. In the patent drawing show in detail

Figure 1:

a U-shaped discharge tube of a high-power radiator according to the prior art based on a technical drawing (partly in section) in a plan view in the direction perpendicular to the plane of curvature,

Figure 2:

a U-shaped discharge tube of a high-power lamp according to the invention based on a technical drawing in a plan view in the direction perpendicular to the plane of curvature, and

Figure 3:

a side view of the high power radiator shown in Figure 2 in the direction parallel to the plane of curvature (partially in section).

Reference number 1 is assigned to the discharge tube shown in FIG . The discharge tube 1, which consists of quartz glass, is bent in a U-shape. Figure 1 shows a plan view of the plane of curvature, which thus runs parallel to the sheet plane. The discharge tube 1 has an outer diameter of 15 mm. The two free legs 2; 3 of the discharge tube 1 are each at their end with a pinch 4; 5 closed. In the bruises 4; 5, each molybdenum foils (not shown in the figure) are melted, which on the one hand with wires 6; 7 for the electrical connection to a voltage source and on the other hand with electrodes 8; 9 are connected.

The bruises 4; 5 are formed over a larger area. The squeeze plane, in which the end face of the discharge tube 1 is fused, runs parallel to the plane of curvature (sheet plane) and in the central axis 10 of the discharge tube 1. The squeezes 4; 5 are symmetrical both with respect to the central axis 10 and with respect to a mirror plane parallel to the plane of curvature.

On both sides of their long sides are the bruises 4; 5 provided with webs 11 which protrude vertically upwards and downwards from the squeezed area.

The length of the bruises 4; 5 - viewed in the direction of the central axis 10 - is approximately 20 mm; their width - this means the dimension perpendicular to the length - corresponds approximately to the diameter of the discharge tube, in this case 15 mm. The strength of the bruises 4; 5 in the squeezed area is approximately 2.5 mm.

It is immediately apparent from the figure that when the discharge tube 1 is loaded in the direction perpendicular to the plane of curvature (sheet plane), the bruises 4; 5 due their small thickness and low sheet resistance in this direction, have a low breaking strength.

The discharge tube 1 is formed in one piece. In the region of the curvature, which is identified in FIG. 1 by the reference number 12, it has approximately the same outside and inside diameters as in the region of the free legs 2; 3. After evacuation and filling with a suitable gas filling via a pump nozzle (not shown in the figure), this is melted down to form a glass plug 13. The glass plug 13, which is formed directly at the tip of the curvature in the radiator according to the prior art (FIG. 1), can easily cause breakage as a surface inhomogeneity.

In the UV high-power lamp according to the invention shown in FIG. 2 , the discharge tube 14 also consists of quartz glass and it is also curved in a U-shape. In this representation too, the plane of curvature runs parallel to the leaf plane.

The discharge tube 14 has a U-shaped elbow 15 which circumscribes an angle of 180 ° and which with the free legs 16; 17 of the discharge tube 14 is melted in a transition region 24. The elbow 15 has an outer diameter of 9 mm and a wall thickness of 1.5 mm; the free legs 16; 17 have an outer diameter of 15 mm and a wall thickness of 1 mm.

The two free legs 16; 17 are sealed gas-tight at each end with a pinch 18; 19. By the bruises 18; 19 are shown similar to FIG. 1, the electrical connections 21 for the electrodes (shown in FIG. 3) are passed through.

The bruises 18; 19 are formed over a larger area. Each squeezing plane, in which the end faces of the discharge tube 14 are fused, runs perpendicular to the plane of curvature (sheet plane). The bruises 18; 19 are both with respect to the axis of symmetry 25 of the discharge tube 14 and with respect to the through the central axes 26 of each leg 16; 17 symmetrical.

The bruises 18; 19 are cemented in a common ceramic base 20, through which in turn electrical connections 21 for connecting the electrodes 9 to the voltage source (not shown) are led out. The bruises 18; 19 are analogous to the bruises 4; 5 (as they have been explained with reference to Figure 1) with a flat top and Provided underside, and on the long sides of which webs 22 project perpendicularly from the pinch plane on both sides. Each long side of the pinch 18; 19 is thus T-shaped. In the illustration according to FIG. 2, only these webs 22 can be seen as a top view of the "T". The webs 22 run parallel to the plane of curvature (sheet plane). The actual bruise 18 extends perpendicularly thereto; 19 and the crush level.

This can be seen more clearly from FIG. 3, which shows a representation of the UV high-power radiator rotated by 90 °. The dimensions of the crimped area 18 correspond to those as explained with reference to FIG. 1, that is to say approximately 15 mm in width, approximately 20 mm in length and approximately 2.5 mm in thickness.

With a force running in the direction perpendicular to the plane of curvature, as symbolized by the direction arrow 23, the orientation of the bruises 18; 19, as shown in the exemplary embodiment according to FIGS. 2 and 3, has a high moment of drag, so that the risk of breakage in this orientation of the bruises 18; 19 is reduced.

The breaking strength of the radiator according to the invention is further increased in that the pump nozzle (not shown in the figure) is placed in the lateral region of the elbow 15, so that the glass plug 13 which forms during melting is arranged in a region which is usually subject to a lower mechanical load is exposed.

Claims (6)

Optical radiator with a light tube bent in a plane of curvature, the ends of which are each closed by means of a pinch formed flat in a pinch plane, through which at least one electrical connection is guided from the outside into the light tube, characterized in that the pinch plane includes an angle in the range between 10 ° and 90 ° with the plane of curvature. Spotlight according to Claim 1, characterized in that the squeezing plane includes an angle in the range between 60 ° and 90 ° with the plane of curvature. Spotlight according to claim 1, characterized in that the crushing plane encloses an angle of 90 ° with the plane of curvature. Radiator according to claim 1 or 2, characterized in that the two squeezes (18; 19) are held in a common base (20). Spotlight according to one of the preceding claims, characterized in that the light tube (14) is U-shaped. Spotlight according to one of the preceding claims, characterized in that the luminous tube (14) has a cross-sectional area in a region of curvature (15) of its bend, viewed in the direction of the longitudinal axis (26) of the luminous tube, which is smaller than the cross-sectional area from both sides regions (16; 17) of the luminous tube (14) adjoining the curvature region (15).

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