US2881909A

US2881909A - Getter holder

Info

Publication number: US2881909A
Application number: US688679A
Authority: US
Inventors: Fransen Jan Josephus Bernardus
Original assignee: US Philips Corp
Current assignee: US Philips Corp; North American Philips Co Inc
Priority date: 1956-11-27
Filing date: 1957-10-07
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14
Also published as: NL212519A; FR1200761A; GB819060A; DE1035799B; NL106420C

Description

April '14, 1959 J. J. B. FRANSEN 2,881,909

- GETTER HOLDER Filed oct. '7. 1957 IN VEN TOR. JJN Jamasmumvsmm BY W @JTJJ AGEN.

United States Patent O GETTER HOLDER Jan Josephus Bernardus Fransen, Eindhoven, Netherlands, assignor to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Application October 7, 1957, Serial No. 688,679

Claims priority, application Netherlands November 27, 1956 3 Claims. (Cl. 206-.4)

The invention relates to a tubular container for a gas binder (getter), out of which container the active substance can escape through a longitudinal opening in the envelope during the evaporation. The invention furthermore relates to an electric discharge tube comprising such a container.

In general, such containers consist of a cylindrical envelope containing the gas binder, for example an alloy of barium and strontium or aluminium. The envelope is cut from a long tube and, as a rule, Welded to a U- shaped strap to permit high-frequency heating. The envelope has a longitudinal slit, obtained for example by local grinding, from which the gas binder can escape during the evaporation. In a further embodiment the cylindrical envelope has a longitudinal groove which bursts open during the evaporation of the gas binder. The escaping vapour constitutes a directional jet and is thus precipitated on a fairly sharply limited part of the bulb of the vessel, which is in general an electric discharge tube, in which the container is housed. A sharp limitation of the precipitated mirror is particularly important with discharge tubes having a plurality Iof electrodes and small dimensions, since the mirror on the bulb has a particular capacity relative to the electrodes and since it is desirable for this capacity to be the same for all tubes of the same type.

It has been found, however, that the size of the surface of the mirror may exhibit considerable dilferences, which are found to be due to vapour of a gas binder escaping at the ends of the tubular container in a direction approximately at right angles to that of the vapor jet escaping from the longitudinal slot. Since the ends of the tubular continer are more or less shut by the cutting and welding operations to fasten it to the strap, the quantity of vapour escaping at these ends is not always the same, so that an unequal extension of the mirror is occasioned on the bulb in different tubes.

The said disadvantages can be completely obviated, if the tubular container for the gas binder is slightly bent in a manner such that a gas binder escaping at the ends has substantially the same direction as the vapour of the gas binder escaping from the longitudinal slot. The tubular container is preferably bent in a manner such that it constitutes parts of a circle, the longitudinal slot lying on the hollow side. The container may, as an alternative, be bent in the form of a U, the longitudinal slot lying also in this case on the concave side. At any rate care must be taken that, when the gas binder in an electric discharge tube is evaporated, the vapour escaping at the ends of the container is precipitated on the same part of the bulb as the vapour escaping from the longitudinal s ot.

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The invention will be described more fully with reference to a drawing in which:

Fig. 1 shows a discharge tube, in which a conventional straight container is housed and Fig. 2 shows a container according to the invention and Fig. 3 shows a tube comprising such a container.

Referring to Fig. 1, reference numeral 1 designates the bulb of the tube in which an electrode system 2 is housed. At the upper end inside the tube a container 3 for the gas binder is secured, this substance producing a mirror 4 in the bulb after its evaporation. It is found that additional mirrors 5 of non-constant dimensions are produced by vapour of the gas binder emanating from the ends of the container 3. Since the dimensions of the mirror as a whole are, consequently, not constant, the capacity of the mirror relative to the electrodes of the system 2 in different tubes of the same type is not the same.

In accordance with the invention the container 6 is curved as is shown in Fig. 2. The longitudinal slot 7 is provided on the concave side. At 10 the cylindrical container 6 is welded to a strap 8, which is welded, as usual, to a supporting rod of the electrode system, as is shown in Figs. 1 and 3.

It is evident from Fig. 3 that the mirrors 11, produced by vapour escaping from the ends 9 of the container 6, are precipitated on the part of the bulb 1 which is already covered with the mirror 4 by the vapour escaping from the longitudinal slot. The dimensions of the mirror 4 are thus not affected by the mirrors 11, so that a constant capacity of the mirror relative to the electrodes is ensured.

Apart from the embodiment shown, other embodiments of the invention are possible. The cylindrical containers may, for example, be bent rectangularly.

What is claimed is:

l. A vacuum tube getter holder comprising a tubular body having a longitudinal slot in the Wall thereof for storing a supply of vaporizable gas-binding material, said tubular body having a longitudinal curvature with the slot on the inner periphery of the curve and the radius of which is such that the gas-binding material emanates from the ends of the tubular member in substantially the same direction as between the ends.

2. A vacuum tube getter holder comprising a tubular body having a longitudinal slot in the wall thereof for storing a supply of vaporizable gas-binding material, said tubular body being in the form of a sector of a circle with the slot on the inner periphery of the circle and having a radius such that the gas-binding material emanates from the ends of the tubular member in substantially the same direction as between the ends.

3. A vacuum tube getter holder comprising a tubular body having a longitudinal slot in the wall for storing a supply of vaporizable gas-binding material, said tubular body being in the form of a sector of a circle with the slot on the inner periphery of the circle and the radius of which is such that the gas-binding material emanates from the ends of the tubular member in substantially the same direction as between the ends and forms a deposit on a remotely disposed surface whose dimensions are determined only by the length of the longitudinal slot.

Ronci Aug. 9, 1927 Gabbrielli Jan. 22, 1957