US1522286A - Method and apparatus for mounting filaments - Google Patents

Description

' 'H. P. CLAUSEN ma'rnon u) APPARATUS FOR MQUNTING mpmnn'rs Filed Feb. 5, 1920 Patented Jan. 6, 1925.

UNITED STATES 4 1,522,286 PATENT OFFICE.

' HENRY ROLAUSEN, OF MAMARO'NEC K, NEW YORK, ASSIGNOR TO WESTERN ELECTRIO" COMPANY, INCOIQPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD AND APPARATUS FOR MOUNTING FILAMENTS.

Application filed February 3, 1920. Serial No. 356,051.

To all whom it may concern:

Be it known that I, HENRY P. OLAUsnN, a citizen of the United States, residing at Mama-roneck, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Methods and Apparatus for Mounting Filaments, of which the following is a full, clear,-

concise, and exact description.

My present invention relates to electrlcal devices and more particularly to electrical lamps or vacuum tubes and it has for its object to improve in the manner of mounting the filaments used in these tubes, particularly when the space between electrodes is small. The improvements have reference to properly tensloning the filament in a new and inexpensive way and to so connecting its ends to the lead-in wires that the attachinents may be conveniently made with freedom exteriorly of the grid structure and the parts then positioned properly between the grids with greater ease than heretofore. To these and other ends the invention resides in certain improvements and combinations of parts all as will be hereinafter more fully described, the'novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a fragmentary side view of a partially finished filament constructed and mounted in accordance with my invention;

Figure 2 is a similar view. of the finished filament of my invention Figure 3 is anenlarged fragmenta detail view illustrative of the various wires, and v Figure 4 is a side view partlybroken away of a vacuum tube 'of a type in which a mode of joining I my Invention may be utilized to advantage.

Similar reference numerals throughout the several viewsindicate the same parts, Referring to the drawings, 1 indicates the tube and 2 the lavite or similar insulating block at the head thereof having dependv ing lateral wires 3 that 4 and 5 and a central hook support the grids 6 supporting the intermediate portion or apexof the looped filament 7. The, ends of the filament are connected to the respective lead-in wires 8' issuing from the stem In the practice of inypresent invention,

I construct my leadein wires 8 of comparw mediate of their length I weld or otherwise 0 secure to each of them one end of a short tensioning 'wire 10. This wire is referably a light weight, hard drawn Wire the tension of which is not easily affected byheat, for instance, molybdenum. The other end of this tension wire is welded or clamped to an end of the filament '7 and at the time the stem assembly is completed, including the grid and filament, this point of'attachment lies outside of the grid as before and as shown in Figure 1. I then use the projecting end portions 11 of the lead-in wires 8 to manipulate themby an inward bend so that theycarrythe ends of the filament to the desired'positions inside of the grids as shown in Figure 2. In doing so, the spring connecting wires 10 are .also carried inwardly and are placed under tension as shown in the same figures, so that the desired tension is communicated to the filament as it hangs upon its central hook support 6.- Great latitude is attained in bending the lead-in wire 8 back and forth to cause the spring 10 tobe placed in any desired positionand the projecting end 11 of the wire forms a very convenient handle for efi'ectingthis bending operation with the greatest ease, it being unnecessary to enter an additional tool of any kind in the narrow space between the two sides of the the outer end of the element 10. The wire 10 may be flattened at a point such as 13 in the manner shown so that the end of the wirehas little or-no lateral give.

It will be noted that my invention does not call for a, spring support. t the top nu have shown an enlarged l i where thefilament is fastened to the top of and I thus permit the use the stem assembly. I place the springs at the bottom where rthe leading in wires are located but overcome the difiicultyof using the molybdenum wire as 'aleading-in wire by Welding it to the comparatively heav wire of any esired appropriate material as a leading-in wire that may prove more satisfactory for this purpose than would molybdenum or similar wlre.

Another feature of importance is that if the leading-in wire is, say, nickel or copper, a material reduction in cost will be obtained through its bein unnecessary to use more than a, very smal amount-of molybdenum wire to secure the desired tension upon the filament. Other wire such as steel or nickel, could be used, particularly in the formation shown in Fi 'ure 3, and have a minimum amount of side play, thus keeping the filament in a central position between the two sides ofv the grid. Extreme variations in temperature result in inch in the length of the filament and in the practice of my invention, this variation is completely absorbed by the tensioniug spring 10 when properly adjusted.

What is claimed is: I

1. A method of mounting vacuum tube filaments which comprises securing in the tube a lead-in wire substantially longer U to intermediate portions of a than its required final length, attachlng an end of the filament to an intermediate portion of said wire, manipulating the free end of said wire to give the filament its position and tension, and then cutting ofi the excess portion of said wire.

2. A method of mounting vacuum tubefilaments, which comprlses'attachin a pair of resilient wires to the ends ofthe lament, attaching'said wires at a substantial angle air of lead-in and-bending'sa-id lead-1n wires to flex wires,

WIIYQS and thereby. tension said said resilient filament. o

3. A method "offlmounting vacuum tube filaments between other electrodes thereof which comprises attaching connecting wires 7 other electrodes and wires in the tube, attac ing a pair of some cases m a van ation of approximately one-sixteenth of an.

menace to intermediateportions of the lead-in wires after the other electrodes are assembled, attaching the ends of the filament to the connecting wires at points exteriorly of the then manipulating the free ends of the lead-in wires to carry the attached ends of the filament between the other electrodes.

.4. A method of mounting filaments in vacuum tubes of the type having an electrode surface at each side of the filament,

a pair of plastic resilient wires to said plastic wires and to the ends of said filament with said ends extending outside the boundaries of said surfaces, and bending said plastic wires to position the filament within said boundaries and to tension the filament.

5. The combination with a vacuum tube filament and a support for one portion thereof, of a support for another portion thereof comprising a wire of plastic material secured in the tube, and a resilient wire attached which comprises securin to said plastic wire and to said other portion, said plastic wire being bent to a position to flex said resilient wire whereby tension is applied to said filament.

6. The combination with a vacuum tube filament and a central support therefor, of a pair ofrelatively heav leadin wires of plastic material, and a light resilient wire connecting each end of the filament to a lead-in wire, said lead-in wires being bentto positions to flex said resilient wires whereby tension is applied to said filament.

7. The combmation'with a vacuum tube filament and a central support therefor, of

a pair of relatively heavy lead-in wires of plastic material, and a ght hard drawn spring wire not easi affected by 'heat connected to each lead-in wire and to an end of the filament, said lead-in wires being bent to positions toflex said sprin wires whereby tension -'is applied'to said filament.

In .witness wher'eofll hereunto subscribe my name this 28th day of January, A. D 1920.

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