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Publication numberUS3714691 A
Publication typeGrant
Publication dateFeb 6, 1973
Filing dateNov 18, 1970
Priority dateNov 18, 1970
Publication numberUS 3714691 A, US 3714691A, US-A-3714691, US3714691 A, US3714691A
InventorsAizawa M, Mori K
Original AssigneeStanley Electric Co Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method for producing sheet supported coiled conductors
US 3714691 A
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Description  (OCR text may contain errors)

Feb. 6, 1973 MASANOBU AIZAWA ETAL 3,714,691

METHOD FOR PRODUCING SHEET SUPPORTED COILED CONDUCTO RS Filed Nov. 18, 1970 2 Sheets-Sheet l Feb 6, 1973" MASANOBU AIZAWA EI'AL 3,714,591

METHOD FOR PRODUCING SHEET SUPPORTED COILED CONDUCTOR Filed Nov. 18, 1970 2 g Japan Filed Nov. 18, 1970, Ser. No. 90,602 Int. Cl. H013 9/18, 9/36 US. Cl. 2925.15 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a method for producing sheet supported coiled conductors and also to various constructions of these sheet supported coiled conductors. In the method, the coiled conductors each wound around a core material are interposed between a required number of supporting sheets made of a material not soluble in a dissolving liquid for the core material and having a plurality of cutout portions therethrough so that a substantial part of the coiled conductors is exposed through the cutout portions, and the whole of the coiled conductors interposed between the supporting sheets is immersed into the dissolving liquid for the core material so that the core material is thereby dissolved and removed from the coiled conductors.

BACKGROUND OF THE INVENTION This invention relates generally to a method for producing a sheet supported coiled conductor and improved constructions of the sheet supported coiled conductor produced by the method.

Heretofore, coiled conductors such as tungsten filaments employed in electric lamps are produced firstly by winding each of the conductors around a suitable core material such as copper wire or iron wire or rod and thereafter dissolving the core material away from the coiled conductors employing a dissolving solution such as aqua regia.

However, in usual cases, the coiled conductors thus produced have been extremely fragile and difficult in handling because they may be easily deformed or partly elongated permanently or cut. Furthermore, when the coiled conductors are of an extremely minute size to the extent that they may be hardly visible by naked eye, handling of the coiled conductors has been more diflicult because they may be easily entangled together, and when the conductors are once entangled, it is too difficult to disentangle these coiled conductors because a slight pull of such weak conductors may easily cause partial elongation or deformation of these conductors and electrical resistance per length of the conductors may be thereby varied, thus causing irregularity in the illumination of the lamps wherein these filaments are employed.

SUMMARY OF THE INVENTION Therefore, the primary object of the present invention is to provide an improved method for producing sheet supported coiled conductors wherein all of the difiiculties found in handling the conventional coiled conductors can be substantially eliminated.

Another object of the present invention is to provide an improved method for producing sheet supported coiled conductors, which is adapted in mass-production of such conductors.

Still another object of the present invention is to provide an improved method for producing sheet supported coiled conductors, wherein the conductors still including the core material are handled to be supported in the United States Patent 0 3,714,691 Patented Feb. 6, 1973 "ice supporting sheets and the core material is thereafter dissolved away from the coiled conductors.

Still another object of the invention is to provide an improved construction of the sheet supported coiled conductors which are adapted to be employed in various fields of applications.

These and other objects of the present invention can be achieved by an improved method for producing sheet supported coiled conductors, which comprises the steps of forming coiled conductors each wound around a core material soluble in a dissolving liquid, providing a required number of supporting sheets made of a material not soluble in the dissolving liquid for the core material and having a plurality of cutout portions formed through the supporting sheets, interposing the coiled conductors still including the core material between each of the supporting sheets so that a substantial part of the coiled conductors is exposed through the cutout portions of the supporting sheets, and immersing the whole of the coiled conductors and the supporting sheets into the liquid for dissolving the core material so that the core material is removed from the coiled conductors and the required sheet supported coiled conductors are thereby obtained.

In another aspect of the present invention, there are provided various forms of the sheet supported coiled conductors produced in accordance with the above described production method, which comprises a required number of coiled conductors which are, in their initial stage of the production, wound around core materials; a plurality of supporting sheets made of a material not soluble in a dissolving liquid for the core materials and having a required number of cutout portions; the above mentioned coiled conductors being interposed between the supporting sheets so that a substantial portion of the coiled conductors is exposed through the cutout portions of the supporting sheets; whereby when the coiled conductors and the supporting sheets are immersed into the liquid, the core materials are dissolved away from the coiled conductors.

The invention will be better understood from the following detailed description of the invention when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS ;IIII of the sheet supported coiled conductors shown in DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, which shows a coiled conductor produced by a method in accordance with the present invention, there is indicated the coil conductor 1 in its initial stage wound around a core material 2 and interposed between a pair of sheets, 3, 3' of a material not soluble in a liquid such as aqua regia which is employed for dissolving the core material 2. Through the pair of sheets 3, 3, a plurality of windows 4, 4' are pro- 'vided so that most of the part of the coiled conductor 1 may be exposed through these windows 4, 4'. Through the pair of the sheets, 3, 3', there are also provided a required number of perforations 5, 5' of a far smaller size which are employed for the guidance of aligning the windows 4 on the sheet 3 with the windows 4' on the sheet 3'.

When the whole assembly of the coiled conductor 1 and the sheets 3, 3' is immersed in a dissolving liquid for the core material, the core material 2 such as iron or copper is dissolved into the liquid, and the coiled conductor 1 remains behind interposed between the two sheets. 3, 3' of a material not soluble in the dissolving liquid such as aqua regia as indicated in FIG. 2.

FIGS. 3 through 8 show various modifications of the coiled conductors produced through the method according to the present invention. Within these drawings, FIGS.

3 and 4 indicate examples of the coil conductors held between two sheets of the above described material. In these examples, a plurality of rows of windows 4, 4' are provided, and a plurality of coiled conductors of a considerable length or of a length slightly larger than the diagonal of the window are held between the two sheets 3, 3'. In a specific example of FIG. 5, the coiled conductors 1 are disposed in such a manner wherein the arrangement thereof in FIG. 3 is superposed on the arrangement shown in FIG. 4. In another example shown in FIG. 6, there is indicated still another construction of the conductor holding sheet wherein a plurality of cutout portions 4a and notches 5a and projections 6, 6' are provided instead of the above described windows 4, 4' and small perforations 5, 5'. Furthermore, as shown in FIGS. 7 and 8, the windows 4' provided in the above described examples in one of the two sheets 3' may be omitted. In such a case, the small perforations 5, 5' may also be omitted because there is no necessity of aligning windows as in the cases of the previous examples.

Although the invention has been described with respect to preferred examples of the conuctor arrangement, it will be apparent to those skilled in the art that various modifications or alterations may also be carried out on these arrangements without departing from the spirit and scope of the present invention as defined hereinbelow.

What is claimed is:

1. A method for producing sheet supported coiled conductors comprising the steps of forming said coiled conductors each wound around a core material, providing a required number of supporting sheets made of a material not soluble in a dissolving liquid for the core material and having a plurality of cutout portions through the supporting sheets, interposing said coiled conductors including said core material between said supporting sheets so that a substantial part of the coiled conductor is exposed through the cutout portions, and immersing said coiled conductors held in the supporting sheets into said dissolving liquid for the core material so that the core material is removed from the coiled conductors.

2. A method as defined in claim 1 wherein said number of supporting sheets are slected to be two and said cutout portions are provided through each of said two sheets at the aligning positions.

3. A method as defined in claim 1 wherein said cutout portions are in the form of a window.

4. A method as defined in claim 1 wherein said cutout portions are in the form of notches.

5. A method as defined in claim 1 wherein said coiled conductors are tungsten filaments, said core material is a copper wire, and said dissolving liquid is aqua regia.

References Cited UNITED STATES PATENTS 2,380,525 7/1945 Hirmann 29-2517 3,346,761 10/1967 Ackerman 2925.l7 X 3,103,061 9/ 1963 Fonoroff et a]. 2.9'l55.55

I. SPENCER OVERHOLSER, Primary Examiner R. B. LAZARUS, Assistant Examiner U.S. CL X.R.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4378631 *Jun 23, 1980Apr 5, 1983The Mead CorporationMethod of fabricating a charge plate for an ink jet printing device
Classifications
U.S. Classification445/29, 216/20, 216/106, 29/423
International ClassificationH01K3/00, H01K3/02
Cooperative ClassificationH01K3/02
European ClassificationH01K3/02