US2874209A

US2874209A - Support or stay member for parts of the electrode systems of electric discharge tubes

Info

Publication number: US2874209A
Application number: US396613A
Authority: US
Inventors: Bisterfeld Karl August
Original assignee: US Philips Corp
Current assignee: US Philips Corp; North American Philips Co Inc
Priority date: 1953-01-21
Filing date: 1953-12-07
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

Feb. 17, 1959 K. A. BISTERFELD 7 SUPPORT OR STAY MEMBER FOR PARTS OF THE ELECTRODE SYSTEMS OF ELECTRIC DISCHARGE TUBES Filed Dec; '7, 1953 Gmss WOOL GLASS W001.

as W0 1- INVENTOR KARL BISTE HJFE 1.13

AGENT United States Patent SUPPORT OR STAY MEMBER FOR PARTS OF THE ELECTRODE SYSTEMS OF ELECTRIC DESCHARGE TUBES Karl August Bisterfeld, Hamburg-Volksdorf, Germany, assiguor, by mesne assignments, to North American Philips "Company, Inc., New York, N. Y., a corporation of Delaware Application December 7, 1953, Serial No. 396,613

Claims priority, application Germany January 21, 1953 7 Claims. (Cl. 174--167) In manufacturing electric discharge tubes, usually mica parts are used for supporting or holding the electrodes. Mica may be satisfactory from the point of view of vacuum but it exhibits a number of limitations in other respects. The elasticity of the mica parts, for example, is often insuflicient in mounting the electrodes. In addition, mica tends to splinter off with the result that the supporting or holding function which the mica parts are expected to perform is only insufficiently fulfilled. In addition, mica is occasionally found to be not completely free of detrimental foreign matter.

Endeavours have been made to avoid the above-mentioned disadvantages by the use of asbestos fabrics as supports or stay members for electrode systems. However, asbestos has comparatively bad insulating properties and high dielectric losses. Furthermore, due to its tendency to be fiuffy asbestos is not very suitable as a structural part in electric discharge tubes, particularly since it can be degassed only with difiiculty. The invention provides a solution enabling the disadvantages described to be avoided.

According to the invention a support or stay member for parts of the electrode systems of electric discharge tube consists of a fabric of quartz threads, glass wool or slag wool which is at least partly pasted with cement.

The use of glass wool or slag wool ensures sutficient elasticity of the supports or stay members. The said threads exhibit a smooth surface; due to this and due to the length of the threads a resilient network is obtainable, the known support members made of the fibrous short staple asbestos wool on the other hand having practically no rigidity.

In order to paste the fabric use may be made of silicon lacquer, silicon resin or a similar material. Such coatings of lacquers or resins cement the fabric in a manner such that it is only gradually actuated by resilient reactive forces and ensures a satisfactory support when the coats have been hardened.

The fabric itself may be manufactured in a variety of textures; that is, it may be dense or exhibit comparatively large apertures. Thus more variety than in the case of the known asbestos fabric is made possible.

The cement may cover the whole fabric or it may only serve to paste the points at which the fabric and the system parts required to be supported engage one another.

Similarly to what is well known in mice. discs the fabrics according to the invention may be provided with radial projections or protuberances at their outer periphery which may also be coated with silicon resin which has not yet been hardened, thus enabling the fabric to be smoothly introduced into the bulb of the discharge tube and ensuring that it engage the bulb wall satisfactorily. In addition, a support member thus prepared and introduced will stick to a greater or less extent to the bulb wall by means of its protuberances.

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in discharge tubes which are subjected to high temperatures it is also possible to provide the fabric according to the invention with a coating made of a ceramic suspension, a rim surrounding the prepared apertures remaining uncovered, with the result that the thread-ends projecting beyond the part covered with ceramic material enable the system parts to be resiliently held. In order to fix the ceramic materials applied they can be se cured by firing in a known manner.

The invention will now be described with reference to the accompanying drawing in which some embodiments thereof are shown by way of example.

Referring now to the figures, Fig. I shows a thin fine fabric made of glass Wool, slag wool or quartz threads which may be impregnated with silicon resin or silicon lacquer. In the punched aperture 1 the electrode parts 3 required to be supported are held by a large number of resilient thread ends.

The apertures acting to accommodate the system parts are not necessarily punched, they may alternatively be formed by pressing a pointed mandrel through the fabric with the result that the electrode parts required to be supported are engaged by threads which have been pushed aside and also ensure these parts to be satisfactorily held.

In the embodiment shown in Fig. 2 the aperture 1a has been made by means of a pointed mandrel.

Fig. 3 finally shows a disc-shaped support or stay member according to the invention in which an aperture 1b has been made. A ceramic suspension is applied to the fabric and secured by firing. The area adjacent the aperture 1b is not covered by the ceramic coating.

What is claimed is:

1. In an evacuated device, an electrode system comprising at least one electrode portion and a support therefor, said support comprising a relatively stiff, self-supporting, at least partly cemented fabric constituted of vitreous insulating flexible material, said fabric having an aperture, said electrode portion engaging a portion of the fabric surrounding said aperture.

2. An evacuated device as claimed in claim 1 wherein the vitreous material is selected from the group consisting of quartz threads, glass Wool and slag wool.

3. An evacuated device as claimed in claim 2 wherein the cement consists of a silicon-containing substance.

4. In an evacuated device, an electrode system comprising at least one electrode portion and a support therefor, said support comprising a relatively stiff, self-supporting, at least partly silicon-cemented fabric constituted of a vitreous insulating material selected from the group consisting of quartz threads, glass wool and slag wool, said fabric having a central aperture, said electrode portion engaging a portion of the fabric surrounding said aperture.

5. An evacuated device as set forth in claim 4 wherein the cement is disposed along the portions of the fabric adjacent the aperture.

6. An evacuated device as claimed in claim 4 wherein the fabric is mounted on a ceramic member.

7. An evacuated device as claimed in claim 4 wherein the fabric is provided with projections along its periphery.

References Cited in the file of this patent UNITED STATES PATENTS 1,837,566 Mcllvaine Dec. 22, 1931 2,224,484 Morrow Dec. 10, 1940 2,626,223 Sattler Jan. 20, 1953