SU45553A1 - A method of manufacturing a spiral filament of a refractory metal for electric incandescent lamps - Google Patents

Description

Filament incandescent bulbs for lamps consisting of a single crystal are made by winding a single-crystal wire along a helix.

However, single-crystal wires, while maintaining their mechanical properties unchanged, when they are used as filaments in a taut state, when rolled up along a helical line, become unsuitable, because some turns of them during combustion are so deformed that the light of the body loses its original form. The same thing happens if you make a spiral thread of wire consisting of several crystals. The reason for this phenomenon is that when winding the wire, the crystal or individual pieces of crystals are subjected to extremely strong bending, and the outer parts of them are significantly stretched, and the inner parts are compressed. Wire in this way

is in a tense state, from which it is trying to free itself. .

The present invention aims to manufacture a spiral filament with the elimination of the aforementioned disadvantages by heating the filament to the temperature required for crystal formation only after ens is given a helical shape.

In FIG. 1 shows the shape of a drawn single-crystal wire during etching; FIG. 2- form of the same helical wire during dressing; FIG. 3- form helical wire, processed according to the proposed method.

Elongated single-crystal wires, during etching, gradually assume a prismatic shape (Fig. 1). If a spiral thread obtained by winding a single-crystal wire is put into the liquid for etching, the etched edges follow the turns of the screw (Fig. 2) and the surrounding screw remains in this way with the cylinder after etching. In the same yarn, the crystal formation in which occurs after it has been given a helical shape, the etched edges no longer follow the turns of the screw, and on all orbits of the crystal (Fig. 3), faceted sections are formed on the outside, which are quite regular, and their size depends on the duration of etching. In order to obtain such filaments, a drawn wire with a fibrous structure is taken, heated to the temperature at which fiber breakup begins, pulled out a little by dragging through a diamond eye, then rolled up along a helix and rolled up in a stationary state until white. It is possible to wind it onto a core of a highly refractory metal before the filament of the final crystal structure in a known manner and also to advance the already well known method together with the core through the high temperature zone necessary for the transformation of the crystal structure, after which the core is removed. At the same time, the speed of advancement should be considerably less than for the transformation of the crystal structure of the drawn wire, in accordance with the shortening due to the screw shape. Although this also forms the final crystalline form, the thread thus obtained when it is strengthened on the supporting core of the incandescent lamp can still be bent, i.e. set in a semicircle, for example, because with a large number of turns that the thread, bending it does not noticeably affect the individual turns, and at the same time, the pieces of crystals.

At the time, like a stretched crystal rolled into a screw, bending

the axis corresponds to the bending of the wire, i.e. for each quarter of a turn it is 90 °; in this case, the crystals or pieces of crystals have a very slight bend, for example, approximately 1 ° for each turn.

To make it possible to use shining bodies of small length and thereby increase the coefficient of efficiency in gas-filled lamps, as well as to simplify the supporting thread device, the thread wound in a screw-like manner can be subjected to secondary winding, after which this screw of the second order together with its core Glow until the springiness inherent in the body disappears and its final crystalline form, consisting of long, not bent crystals, is formed.

The heating of the light of the naked body can be produced either by passing an electric current through it, or by supplying heat from the outside, for example, in a suitable tube furnace.

Since the removal of the core after the final incandescence can be difficult under certain circumstances, it is possible to do otherwise, namely, to heat the second-order screw together with the core until approximately 1900-2000, and then heat up one of the luminous bodies, carefully preceded by heating the spring without a core to a significantly higher final temperature. This last heating of the body light, performed after the core has been removed, can also be carried out after installing the light body body on the stem of the incandescent lamp, and it should be ensured that during the process of those machining, the light of the body body does not sag and deform.

It is also possible to use ordinary predominantly containing oxide of thorium tungsten wire as a starting material, without subjecting it to preliminary treatment, especially in cases when the diameter of the first-order screw is relatively small. According to the inventors, the transformation of the crystalline form and

the growth of long crystals occurs more successfully, even without special thermal-mechanical pretreatment, in the case when the diameter of the first-order screw core and hence the diameter of the screw itself is small, being, for example, only two or three times as large as the wire diameter . In the use of hitherto simple spiral luminous bodies, the use of such a small diameter of the core entailed the inconvenience that the length of the light w, of its body was very significant. In the case under consideration, the small diameter of the core of the first-order screw does not cause any inconvenience, since compactness is necessary and the light of a small body of the body is small enough to form a second-order screw. At the same time, it is sufficient that the second-order screw diameter is ten times the diameter of the wire.

The subject matter of the invention.

1. A method of manufacturing an incandescent spiral filament of refractory metal for electric incandescent lamps, consisting of a single crystal or several pieces of a crystal, characterized in that the filament is heated to the temperature required for crystal formation, after it is shaped into a helical shape.

2. Acceptance of the method described in paragraph 1, characterized in that the initial thread, wound on a core of refractory metal, along with the core, is pushed through a high temperature zone to make the thread crystalline.

3. Acceptance of the method described in claim 1, characterized in that the thread wound in a helical manner is subjected to secondary winding to obtain the thread twisted along a helix and then heat-treated to the thread in a crystalline form.

4. Acceptance of the implementation described in paragraphs. 1 and 3, characterized in that the diameter of the first order screw is two or three times the diameter of the thread, and the diameter of the second order screw is at least ten times the diameter of the thread.

5. Acceptance of the implementation described in paragraphs. 1-4, characterized in that the thread pre-wound in the form of a screw of the first order is re-wound on the core to form a second screw of the second order and the thread is heated together with the core to 1900-2000 ° and then the thread without the core is heated to the required higher temperature.

to the patent of a company from the company oi. rep. Nakalivapi electric lamps Patent-Treygand № 45553

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