US1210540A - Cathode-ray tube. - Google Patents

Description

H. E. R. RUKOP & W. K. M. SCHLOEMILCH.

CATHODE RAY TUBE.

APPLlCATlON FILED OCT. 28. 1915.

Patented Jan. 2, 1917.

HANS EWALD REINHOLD BUKOP AND WILHELM KUNO MAX SCHLOEMILCE, 0F BERLIN, GERMANY, ASSIGNORS TO GESELLSCHAFT FI I IR DRA'HTLOSE TELEGRAI'HIE M.-IB.-H., 0F BERLIN, GERMANY, A COBPQBATION OF GERMANY.

oa'rnonn-nar TUBE.

Specification of Letters Patent.

Patented Jan. 2, 1%

To all whom it may concern;

Be it known that we, HANs' EWALD REIN- HOLD Honor and WInHELM Keno MAX SGHLOEMILCH, subjects of the German Emperor, and residing at Berlin, Germany, have invented certain new and useful Improvements in Cathode-Ray Tubes, of which the following is a specification.

Our invention relates to cathode ray tubes which do not work with diluted gases but, as pure electron tubes, under a high vacuum and in which in addition to the anode a special auxiliary anode is provided. Cathode ray tubes of this kind are employed as amplifying relays, generators of oscillations or the like. Experience has shown that, for producing the most favorable effects with tubes of the class referred to, the

mode of arrangement of the heating cathode as well as its distance from the auxiliary anode are important. Certain difiiculties have been experienced from tubes of this class by reason of the mode of arranging the glowing cathode relatively to the auxiliary anode as heretofore employed. In manufacture, for instance, it was difiicult to maintain the necessary small distance between the electrodes; in operation variations of the distance of the electrodes were encountered.

The object of the present invention is to obviate such difiiculties.

According to the present invention the heating wire of the cathode together with its conductor are arranged at right angles to the plane arrangement of the heating cathode has the advantage that in manufacture the heating wire may be located in the direct proximity of the auxiliary anode without exposing the construction to a short circuit between the electrodes. Lateral oscillations of the heating cathode do not efiect a change of the distance between the heating cathode and the auxiliary anode. Thus, the o eration will not be interrupted thereby. oreover, the efiiciency of the cathode is materially increased as compared with the arrangements heretofore employed. The construction of the glowing cathode is immaterial to the invention. he glowing wire may be shaped in the form of a simple loop or of a spiral. For operating the tube with alternating current of high frequency it is preferable to provide a glowing cathode consisting of sevof the auxiliary anode. This eral heating wires connected in parallel. Such glowing cathodes are suitable for very high loads and for tubes which are employed for generating oscillations. It is also preferable to surround the glowing cathode with a screen device at those portions which are not opposite the auxiliary anode. By the screen device the electrons laterally emitted from the glowing cathode are prevented from heating the glass wall of the tube. If a potential, 6. 9., that of the glowing cathode or a higher potential, is applied to the screen device, which preferably con sists of metal, this will have the favorable action that the electrons hitting the screen device will be reflected, thus strengthening the stream of electrons to the anode.

Several constructional forms of the tube in elevation and section are shown in the accompanying drawing. I

In the arrangement according to Fig. 1, 1 is the glass body of the tube and 2 the filament of the cathode forming a simple loop which is connected with the conductors 3. According to the invention the filament 2 with its conductors 3 is arranged at right angles to the plane of the auxiliary anode 4. The latter is formed by a metallic spiral (see Fig. 2) which is stiffened by a glass rod 5 and thereby rigidly connected with the anode 6 consisting of a metallic disk, thus forming a self-sustaining body. 7 and 8 are the conductors to the anode and auxiliary anode.

Instead of employing as a filament a single wire 2 bent to a loop, several wires connected in parallel may be provided, as shown in Fig. 3. This construction is especially adapted for amplifying alternating currents of high frequency. It also allows the use of considerably higher tensions for the filament than the simple constructional form shown in Fig. 1, and is, therefore, especially adapted for tubes employed for generating oscillations.

It is evident that the arrangement of the filament at right angles to the auxiliary anode facilitates in manufacture the maintenance of a definite small distance between tance between'the parallel electrodes could l i l only be attained with great skill of the glass blower. In the manufacture of the tube according to the present invention the insertion of the heating body and of the anode by fusing the glass supports is just as simple as the insertion of the filaments into an ordinary incandescent lamp.

With a view to preventing the electrons emitted laterally of the glowing cathode from damaging the adjacent glass wall of the tube a cone shaped screen 9 is provided forming a jacket and being supported by arms 11 of the glass body. This screen may consist of insulating material as glass or the like, or of metal and may have other suitable forms than those shown. If a metallic screenis employed, it is preferable to conmeet it by a conductor 12 with a source of energy. The conductor may be directly connected with the potential of the glowing cathode or a higher potential may be applied to it. By the potential thus applied to the screen the electrons hitting the screen are reflected and serve for strengthening the stream of electrons flowing to the auxiliary anode.

Experiments have proven that the lateral radiation of heat and emission of electrons is particularly violent in certain directions depending upon the shape of the glowing cathode. It is, therefore, not necessary to extend the screen or jacket around the whole glowing cathode, but it is suflicient to provide smaller screens at the portions having the most intense lateralradiation. An arrangement of this kind is shown in Fig. 4.

By arranging the glowingv cathode with its conductors at right angles to the plane of a the auxiliary anode the manufacture of such tubes is materially simplified. In manufacture it is preferable to employ a tube having two openings opposite each other. Into the openings plugs are. fused one of which, for instance that in the bottom, serves as a support for the anode and the auxiliary anode, whereas the other at the top, serves as a support for the glowing cathode. This construction will also be apparent from Fig. 4. In this figure, 1 is the glass body of the tube. The bottom part 13 supports the auxiliary anode 4 and the anode 6 which are both kept a certain distance apart by the glass support 14. The cover 15 and the glass yoke 16 connected therewith serve as a support for the glowing cathode2 and the two laterally arranged screens 17 It is evident, that by this mode of construction the manufacture of the cathode tube is materially simplified. Thus, the cover may be exactly adj usted and the filament located very closely to the grid 4.

Claims:

1. In a cathode ray tube having a high vacuum, an anode, an auxiliary anode, insulating blocks connecting said anode with said auxiliary anode, and a glowing cathode perpendicularly arranged to the plane of said auxiliary anode.

2. In a cathode ray tube having a high vacuum, an anode, a spiral forming an auxiliary anode, stiffening means for said auxiliary anode, and a glowing cathode perpendicularly arranged to the plane of said spiral.

3. In combination a glass tube, an anode and an auxiliary anode therein, a common support for said anode and auxiliary anode, attached to said tube, a glowing cathode perpendicularly arranged to the plane of said auxiliary anode and supporting means for said cathode independently of said common support.

4. In combination, a glass tube, an anode, an auxiliary anode therein, a common su port for said anode and said auxiliary anode forming the bottom part of said tube, a glowing cathode perpendicularly arranged to the plane of said auxiliary anode and supported by a block forming the cover of said tube.

5. In combination, a glass tube, an anode, an auxiliary anode therein, a common support for said anode and said auxiliary anode forming the bottom part of said tube, a glowing cathode perpendicularly arranged to the plane of said auxiliary anode and supported by a block forming the cover of said tube, and means for strengthening the stream of electrons from saidcathode to said anode.

In testimony whereof we affix our signatures in the presence of twowitnesses.

DB. HANS EWALD REINHOLD RUKOP. WILHELM KUNO MAX SCHLOEMILCH. Witnesses:

HENRY HASPER, ARTHUR Sermononn.

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