WO2009000633A1

WO2009000633A1 - Helix, and method for the production of a helix

Info

Publication number: WO2009000633A1
Application number: PCT/EP2008/057147
Authority: WO
Inventors: Anton Dambacher
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2007-06-26
Filing date: 2008-06-09
Publication date: 2008-12-31
Also published as: DE102007029372A1

Abstract

The invention discloses a double helix made of tungsten, having singularly coiled helix tails, the windings of which are positioned next to each other, encasing a core wire, and shielding the same from the acid in the acid bath during the production process of the helix.

Description

description

Helix and method of making a helix

Technical area

The invention is based on a helix, in particular a double helix, an electric lamp according to the term of claim 1 and its Herstellungsverrahr- ren.

State of the art

The document DE 195 38 497 C2 discloses a manufacturing method of an electric lamp with a filament made of tungsten, which has a core wire in the coil ends, which leads to increased strength and better hold of the coil ends and prevents them from twisting. In the production of a Such a coil, a helical wire is wound around a core wire and then covered the coil ends with paraffin. The helix is then immersed in an acid bath dissolving the core wire, the core wire in the helix ends being protected by the paraffin from acid attack. After the acid bath, the paraffin is removed from the coil ends by boiling the coil in solvent. A disadvantage of this solution is that the covering of the coil ends with paraffin and the removal of the paraffin after the acid bath leads to high manufacturing and manufacturing costs. Presentation of the invention

The object of the present invention is, on the one hand, to create a helix, in particular a double helix, which has high strength and rigidity and, on the other hand, a production method for this helix, which has low production and manufacturing costs and corresponds to high quality standards.

This object is achieved with regard to the helix by the features of claim 1 and with respect to the method by the features of the independent claim 6.

Particularly advantageous embodiments can be found in the dependent claims.

The helix according to the invention, in particular for electric lamps, consists of a coiled middle helical section, which is adjoined by helical outlets wound around a core wire, in which case the turns of the helical outlets rest against one another.

A helix having a coiled central helix section, followed by helical windings wound around a core wire, is wound using at least one core wire with turns adjacent to the helix terminations and then immersed in an acid bath, the at least one core wire etched out of the helix with the exception of the turnarounds, with the adjacent turns substantially shielding the core wire from the acid.

With the adjacent turns the highest winding density is achieved. The slope of the turns in the central coil section is preferably larger and adapted according to the optimum lamp and light properties. Due to the high winding density or number of turns, the spiral outlets together with the core wire can achieve a very high rigidity, as a result of which these and the entire coil have greater robustness against, for example, external forces. Due to the rigid filament outlets, furthermore, a very exact positioning of the filament is possible, for example when soldering with a power supply or when being introduced into a lamp bulb.

Usually, prior art helices have only a single continuous turn pitch, which is predetermined by the pitch of the turns in the central helix section or luminous element. The different winding pitch in the helical outlets and the central helix section of the helix according to the invention makes it possible for the turns to be wound adjacent to one another in the area of the helical outlets without the turns in the central helix section having the same pitch, thus adapting the pitch to the optimum luminous body properties regardless of the slope of Wendelabgänge is given.

The central helix section of the helix can advantageously be double-wound and thus form a double helix. The core wire could be somewhat withdrawn in the end regions of the respective helical outlets and / or towards the central helix sections due to the manufacturing process. The helix is preferably made of the material tungsten and the core wire of molybdenum or iron.

To produce the helix, the helical wire is wound around the core wire, wherein the turns in the helix offs are preferably wound on one another and are substantially spaced apart in the middle helix sections. The central helix section is wound, for example, into a double helix. The wound coil may then be dipped in an acid bath to etch out the core wire, wherein the filament outlets, through the abutting turns, wrap the core wire substantially as a protective sheath and shield it from the acid and retain it in that area of the coil.

Thus, a very inexpensive and fast manufacturing process can be achieved because this coil does not have to be dipped separately in, for example, wax before the acid bath, which would have had to be removed after the acid bath. Furthermore, no wax residues on the helix are possible, which could disturb the halogen cycle process. In addition, it is not necessary to introduce a separate wire or support wire in the Wendelabgänge.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to two exemplary embodiments. The figures show: 1 is a front view of a first embodiment of a coil of an electric lamp according to the invention;

2 shows a cross section through a helical departure of the helix according to the first embodiment;

3 shows a segmented endless winding according to the first embodiment; and

Fig. 4 is a front view of a second embodiment of a coil according to the invention.

Preferred embodiment of the invention

FIG. 1 shows a coil 1 which can be used in particular for general-purpose incandescent lamps, signal lamps, halogen incandescent lamps or photographic lamps. The helix 1 has a central helix section 2, which is double wound from a helical wire 4, and two adjoining single helix helixes 6. The transition between the helix sections 2, 6 can be seen by the different pitch of the helix 4 turns. The pitch of the helical outlets 6 is selected so that the turns substantially abut each other, in the central helix section 2, however, which serves as a luminous body, the pitch of the turns is larger, whereby they are spaced. The helical wire 4 is made of the material tungsten.

FIG. 2 discloses a sectional illustration of the helical departure 6 of the helix 1, the section extending along the section line AA from FIG. The helical wire 4 is wound around a core wire 7 made of the material molybdenum. Danish wrapped. As a result, and by the adjacent turns in the Wendelabgängen 6, the rigidity of this Wendelabgänge 6 is substantially increased. The increased rigidity of the helical outlets 6 results in that the central helix section 2 (see Fig. 1) is better and more firmly held and the helix 1 is therefore more robust overall than, for example, impacts which may occur during operation of an electric lamp. In addition, a twisting of the turns of the helical outlets 6 due to the core wire 7 from FIG. 2 is made more difficult. When installing the coil, it can be positioned very precisely due to its high rigidity and, for example, very precisely soldered or welded to power supply lines.

The core wire 7 from FIG. 2 does not completely fill the helical outlets 6, but its length L is somewhat shorter than the length X of the helical outlets 6, so that the core wire is slightly retracted in the end region 10 and in the transition region 12 towards the central helix section.

In the production of the helix 1, first the helical wire 4 is wound around the core wire 7 (see Fig. 2) on a primary helix winding machine in a first helical winding operation, the pitches of the helices being changeable, depending on whether the helix 4 is for a later spiral outlet 6 (see Fig. 1) or middle coil section 2 is wound. For the helical departure 6, the turn pitch is selected so that the turns abut each other and thus completely cover the peripheral area of the core wire 7 in the helical departure 6 and form a kind of protective sheath or protective sheath. In the first spiral winding operation is thus a Art segmented endless wrapping generated with different pitch ranges of turns.

FIG. 3 shows the segmented endless winding 8 from the above-described part of the production method. Each segment of this endless wrapping 8 has two spiral outlets 6, each delimiting the central coil section 2. Cutting segments 9 or cutting interruptions are introduced between the segments of the endless roll 8 during winding of the helical wire 4 on the primary helical winding machine, which consists of a half wrap of the turn around the core wire 7 (see FIG. 2), which is not shown in FIG. In this case, this turn is not wound adjacent to the adjacent windings, so that the core wire 7 (see FIG. 2) is exposed in sections in this cutting section 9. Such a continuous winder 8 is converted in a second helical winding operation on a helical winding machine producing secondary winding into a double-wound helix 1 (see Fig. 1) by winding the middle helical section 2 a second time, at which two single helical helix discharges 6 connect. The double-helical coils 1 furthermore form an endless winding 8. A double-helix 1 is also referred to as a double helix 1.

The endless winder 8 is annealed after being wound to increase the stability and rigidity of the double helix 1.

The endless wound 8 made of double helixes 1 is completely immersed in an acid bath or mixed acid bath in a next process step, wherein the core wire has 7 is etched out in the region of the central coil section or of the luminous element 2 and in the region of the cutting sections 9, since the adjacent turns of the coil outlets shield the core wire 7 from the acid. In the helical openings 14, 16 (see Fig. 2), which are located in the end region 10 and transition region 12, acid still passes to the core wire 7, whereby this is slightly degraded in these areas 10, 12 and tip-like core wire ends 18, 20 formed become. The core wire is retained after the acid bath in the area of helical outlets 6. It should be noted that immersion of the endless roll 8 into the acid bath takes place only until the core wire 7 has been etched out completely in the region of the middle spiral section 2. The endless wrapping 8 is immediately removed from the acid bath upon reaching this state, so that the core wire 7 in the end region 10 and transition region 12 is not degraded further.

After these process steps described above, the double helices 1 in the region of the cutting sections 9

(see Fig. 3) separated from the endless winder 8, for example with a cutting tool. Since the core wire 7 is etched out in this area in the acid bath, this is done

Separating the double helixes 1 only by cutting through the helical wire 4 in the cutting section 9.

In the double helix 1 of Figure 1 is a transverse spiral, in which the helical outlets 6 extend perpendicular to the filament axis 22 and extend approximately parallel to each other. FIG. 4 shows a second exemplary embodiment of a double helix 24. The helical outlets 6 are bent in each case in a bending region 26, which is in the region of the respective helical departure 6 with adjacent turns to approximately a right angle and extend substantially parallel to the filament axis 28 of the filament 30. This double helix 24 is in this arrangement also called axial spiral. In these bending regions 26 of the helical outlets 6, the turns no longer abut each other in the region of the outer bending radius, whereby in the manufacturing process acid, in the acid bath process step described above, would get between the turns to the core wire (not shown) and be etched out , For this reason, in such a double helix 24, the bending regions 26 are covered with wax, for example, before the acid bath, so that the core wire is also protected from the acid in the acid bath in this region and is retained.

The invention is not limited to the embodiment explained above. As core wire material, for example, iron would also be suitable instead of molybdenum.

Disclosed is a double helix 1 made of tungsten, which has simply coiled Wendelabgänge 6, the turns abut each other, corresponding to a gradient factor 1, and encase a core wire 7 and shield this in the manufacturing process of the helix from the acid in the acid bath.

Claims

claims

1. helix, in particular for electric lamps, with a coiled middle helical section (2) to which a core wire (7) wound Wendelabgänge (6) connect, characterized in that the turns of the Wendelabgänge (6) abut each other.

2. coil according to claim 1, wherein the central coil section (2) is double-wound.

3. coil according to claim 1 or 2, wherein the core wire

(7) is slightly withdrawn in the end regions (10) of the respective helical outlets (6) and / or to the middle helical sections (2).

4. Spiral according to one of the preceding claims, wherein the helix (1) consists of the material tungsten and the core wire (7) made of molybdenum or iron.

5. Spiral according to one of the preceding claims, wherein the pitch of the turns of the central helix section (2) is greater than the pitch of the turns of the helical outlets (6).

6. A process for the production of a helix with a coiled middle helix section (2), to which helical outlets (6) wound around a core wire (7) follow, with the following working steps: Winding the helix (1) with turns adjacent to the helical outlets (6) using at least one core wire (7),

- Form annealing the coil (1), - immersing the coil (1) in an acid bath and

Etching out the at least one core wire (8) from the coil (1), with the exception of the spiral outlets (6), wherein the adjacent turns substantially shield the core wire (7) from the acid.

7. The method of claim 6, wherein the winding of the helix (1) is carried out with the following steps: - winding the helix (1) around a core wire (7) on a first helical winding machine, wherein the turns in the helical outlets (6) adjacent to each other are wound and are substantially spaced in the central coil sections (2),

- Winding the central coil portion (2) to a double helix (1) on a second helical winding machine.