JPH046065B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a method for manufacturing a tungsten coil filament having a skipped portion for forming a linear coil leg portion of an incandescent lamp or the like.

[Technical background of the invention and its problems]

For example, tungsten double coil filaments used in incandescent light bulbs are manufactured by winding a single coil filament around a primary mandrel made of iron or the like, and then winding it around a secondary mandrel made of molybdenum. This type of tungsten coil filament needs to be formed with substantially direct coil legs at both ends in order to facilitate automation of supply and wire connection operations in the production of incandescent light bulbs. FIG. 2 is a perspective view showing the main parts of a conventional secondary winding machine, in which a molybdenum secondary mandrel 2 is continuously fed out from the center hole of the nozzle 1, and rotates around the axis of the nozzle 1. A single coil filament 6 (in Fig. 2 (It is indicated by a line.)
is wound to produce a double coil filament 7. When a double coil of the required length is wound, the nozzle 1 stops rotating, and the nozzle 1 stops rotating by the length of the coil leg 8.
A single coil 6 is sent out without being heavily coiled to form a coil leg 8. A metal flying part shaping guide jig 10 supported by the arm 9 is pressed against the coil filament to maintain the linearity of the coil leg when the single coil 6 forms the coil leg 8. Conventionally, a guide jig 10 is fixed at the position shown in the figure, and the guide jig 10 is used not only when forming a coil leg but also when winding a double coil. It was pressed against. Therefore, when winding a double coil, dents or scratches 12 due to pressure contact may occur on the filament as shown in the enlarged view of FIG. 3. The dents and scratches may cause the filament to break due to vibrations during the manufacturing process of the light bulb in which the coil filament is used or during transportation of the completed light bulb.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and has few dents or scratches on the coil filament, and even if they occur, they are minor and there is no fear of filament breakage, and therefore the desired characteristics can be maintained. An object of the present invention is to provide a method for manufacturing a tungsten coil filament used in incandescent light bulbs, etc., which can fully demonstrate its lifespan.

[Summary of the invention]

When manufacturing a tungsten coil filament, the present invention involves separating a guide jig for shaping the skipped portion from the coil filament when winding the coil portion, and rotating the guide jig to bring it into contact with the filament when shaping the skipped portion. This is a method for manufacturing a tungsten coil filament, which is characterized by shaping a tungsten coil filament.

[Embodiments of the invention]

The details of the invention will be described with reference to FIG.

In the upper part of FIG. 1, a double coil filament 16 is shown in which a coil filament 14 (a single coil filament is shown by a line) is wound around a mandrel 13 and has a skip portion 15 in the middle thereof. In addition, (A) to (C) show the time schedule of the coiling head and guide jig, and (A) shows the time schedule of the coiling head and guide jig.
The coiling head (corresponding to (3)) rotates and winds the double coil, and () is the period during which the coiling head is turned on. (B) shows the movement of the guide jig for shaping the skipped portion 15. As shown in (B), the present invention is designed to prevent the skipped portion from forming when winding the double coil portion shown in (A) (between dashed line A and dashed line B). The shaping guide jig 10 comes into contact with the coil filament 14 by the movement of the arm 9 shown in the second figure, and performs the operation shown in parentheses, thereby shaping the skipped portion 15. That is, the guide jig 10 comes into contact with the filament 14 at the end of winding the coil (a), and separates from it at the beginning of winding (b). The jig 10 is rotatably held by means such as a shaft support. OFF indicates a period of inactivity. For comparison, (C) shows the state of a conventional guide jig for shaping the skipped portion, and as shown in (), the guide jig is in constant contact with the filament.

〔Effect of the invention〕

When manufacturing a tungsten coil filament, the present invention involves separating a guide jig for shaping the skipped portion from the coil filament when winding the coil portion, and bringing the rotatable guide jig into contact with the filament during shaping the skipped portion. A method for producing a tungsten coil filament characterized by shaping the coil filament, in which a guide jig for shaping the skipped portions constituting the coil legs is separated from the coil filament during coiling. There will be no dents or scratches on the main body part, and when shaping the skipped part, the guide jig rotates due to contact with the filament, so there is less friction, and there is less impact on the filament than when a stationary guide jig contacts. Very few marks or scratches occur. The disconnection that occurred in the conventional light bulb manufacturing process was around 0.2% to 0.3%.
We were able to reduce the number by 0.005%, or about 5 out of 100,000, to almost zero.

In addition, FIG. 1 shows an example in which the guide jig starts contacting the filament at the same time as the operation of the coiling head stops, and coiling starts at the same time as the guide jig separates, as an embodiment of the present invention. The guide jig may come into contact with the filament just before the coiling head stops, and the coiling head may move just before the guide jig separates, so that there may be some progress or delay in the approach and separation of the guide jig. Note that if the guide jig is not in contact with the filament when the coiling head stops rotating, there will be no dents, but the straightness of the flying parts that become the coil legs will be impaired and the coil filament will break during the light bulb manufacturing process. This is not desirable as there is a risk of mistakes occurring. Therefore, in the present invention, the guide jig for shaping the skipped portion only needs to be separated from the coil filament when the coil portion is wound.

Further, in the embodiment, an example in which a single coil filament is double coiled has been described, but it can also be applied to a case where a tungsten wire is formed into a single coil having a skipped portion, and the same effect as described above is exhibited.

[Brief explanation of drawings]

FIG. 1 is a time schedule diagram showing the relationship between the movement of the coiling head and the movement of the present invention and the conventional guide jig for shaping the skipped part. FIG. 2 is a perspective view showing the state of the conventional coiling head during coiling. FIG. 3 is a partially enlarged view of a conventional coil filament. 2, 13... Mandrel, 6, 14... Single coil filament, 7, 16... Double coil filament, 10... Guide jig for shaping the skipped part,
15... Skip section.

Claims (1)

[Claims] 1. A method for manufacturing a tagsten coil filament in which a tungsten wire or a single coil tungsten filament is wound around a mandrel to form a coil portion, and the winding on the mandrel is stopped to alternately form straight skipped portions, A tungsten coil characterized in that when winding the coil part, a guide jig for shaping the skipped part is separated from the coil filament, and when shaping the skipped part, the rotatable jig is brought into contact with the skipped part to shape the skipped part. Method of manufacturing filament.