US2146374A - Getter - Google Patents

Description

A. J. KING Feb. 7,1939.

GETTER Filed Sept. 10, 1934 mmvrbk aka/Ting L.

- fla'e BY kn j ATTORNEY l harmful gases.

Patented Feb. 7, 1939 UNITED STATES GETTER Aden J. King, Syracuse, N. Y., assignor to King Laboratories tion of New York Inc., Syracuse, N.

Y., a corpora- Application September 10, 1934, Serial No. 743,355 3 Claims. (01. 250-275) This invention relates to getters for evacuated tubes, such as radio tubes and the like.

In the manufacture of radio tubes it is customary to employ getters to remove the last traces of gases which might otherwise interfere with the life and operation of the tube. This getter is ordinarily in the form of a small quantity of material which can be flashed; that is, heated to the point where it will chemically unite with the This material is carried upon a small metallic plate within the tube and after means as, for example, induced electric currents.

With the getters heretofore employed there has been a tendency of the getter to spatter during the flashing, with the possibility that particles of the heated material may lodge on the assembly to spoil the operation of the tube, or on the en- 30 velope to crack the glass, destroying the tube.

It is an object to provide a getter which will be effective for conditioning the atmosphere within the tube but which will be free from any danger of splashing the getter material to the damage of the tube.

The attempt to remedy this difficulty by placing the getter in the envelope with the getter material on the underface of its supporting plate is helpful in that material thrown from the getter is kept from reaching the assembly and the upper portions of the envelope, but it still may be cast upon the lower portion of the glass. More over, with such a getter there is a tendency of the material to drop olT its supporting plate as soon as it melts, before it is properly flashed.

A fine wire screen placed over the getter material and welded to the getter plate serves in some measure to prevent the issuance of some of the larger particles of material but it is not completely effective and it of welding the screen to increases the expense.

In accordance with this invention, the advantages of preventing the upward projection of i the particles is achieved in a simple and inexpensive way, while at the same time the lower part of the glass is also protected. In the preferred form or the invention, moreover, the getter is supported upon the upper face of its plate so that there is no tendency to drop off any molten material before it is completely flashed.

The invention accordingly comprises a product possessing the features, properties, and the relation of components which will be exemplified in the product hereinafter described and'the scope adds another operation the plate, which unduly of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description, taken in connection with the accompanying drawing, in which:

Figure 1 is a cross section of a radio tube embodying this invention.

Figures 2 and 3 are respectively an enlarged 1 section of the getter in its preferred form and a top plan View thereof.

Figures 4 and 5 are respectively similar views of a modified construction. g

In Figure 1 the numeral l0 represents an envelope of glass or the like, having a glass pillar II extending upwardly in the center thereof, to support the functioning elements. The numeral l2 represents a suitable base upon which tube may be mounted. The operating parts comprise the assembly l3 carried by the pillar II. Extending downwardly from the assembly is a supporting wire l4 carrying the getter l5.

In its preferred form this getter comprises a thin metallic sheet having a vertically projecting apron I6 adapted toshield the pillar from any particles that might possibly issue from the getter material and a horizontal portion l1 and a tab l8, which is folded beneath the portion l1.

Thetab l8 has a depression forming a pocket l9, facing upwardly against thehorizontal portion I! of the getter plate and this pocket l9 carries the getter material 20, which may be pressed in, or otherwise held. in place. The getter may be supported in any convenient way to the supporting wire M as, for example, being spot-'- Welded thereto.

When the getter, so arranged and so mounted, is fiashecL'it will be clear that the material is protected by the pocket I9 from falling downwardly, even though it be in a fused condition and any particles thrown off from it will be immediately projected upon the underside of the plate [1, adhering to that plate until completely vaporized. The getter, however, can have its full effect upon the gases within the tube through the opening between the tab l8 and the horizontal portion.

In this form of the invention it would be clear that every direct line of motion between the body of the getter material and the inside of the tube is intercepted by some portion of the getter plate; while, at the same time, the full value of the getter material is utilized in the operation. For this reason tubes having a getter of this construction may be. flashed at a higher rate than is customary since even ebullition of the getter material will not throw particles upon parts of the tube.

In the construction shown in Figure 4 there is illustrated a different form, having some advantages of the preceding. In this construction the horizontal portion Ha. of the getter plate is, itself, provided with an inverted pocket l9a to contain the getter material and the tab la is arranged to extend below the pocket to prevent any of the getter material from dropping out of it.

This tab I8a. may, if desired, be provided with openings 22 to facilitate the communication between the getter and the gases within the tube; these openings, however, being so fine that no particles of material size can be projected through them. This construction is superior to the form of getter in which the screen material is used, for it is a simpler matter for particles of material to pass through adjacent meshes of a mesh screen than it is through a separated opening in a metal plate.

In the construction of Figure 4 it will be clear that the openings 22 may be omitted, if desired, so that any particles of the material thrown off may be caught by the tab. In such case the functioning of the device would be similar to that of the first modification.

Since certain modifications may be efiected in the above product without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall 'therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A device of the character described for use with an electron tube comprising, a getter structure formed integrally in one piece of a single sheet member independent of the elements of the tube having a principal portion and a tab portion bent at one edge of said principal portion reentrantly back upon said principal portion in close relation thereto but spaced therefrom, one of said portions having a recess adapted to receive getter material which recess is covered by the other of said portions, said principal portion being provided with an apron substantially perpendicular to said principal portion and being formed by bending said sheet member about an edge of said principal portion opposite the edge at which said tab portion is bent and in the direction of the same face thereof as faces said tab portion.

2. In an electron tube structure comprising a unit of operating electrodes mounted about a longitudinal axis of said tube and further comprising a base portion for supporting said unit, a getter structure formed integrally in one piece of a single sheet member independent of the elements of the tube having a principal portion and a tab portion bent at one edge of said principal portion reentrantly back upon said principal portion in close relation thereto but spaced therefrom, one of said portions having a recess adapted to receive getter material which recess is covered by the other of said portions and getter material held within said recesses, said principal portion being provided with an apron substantially perpendicular to said principal portion and formed by bending said sheet member about an edge of said principal portion opposite the edge at which said tab portion is bent and in the direction of the same face thereof as faces said tab portion, and means for mounting said getter structure in said tube with said principal portion substantially perpendicular to said longitudinal axis of said tube and on the base side of said electrode unit.

3. In an electron tube structure comprising a unit of operating electrodes mounted about a longitudinal axis of said tube and further comprising a base portion for supporting said unit, a getter structure formed integrally in one piece of a single sheet member independent of the elements of the tube having a principal portion and a tab portion bent at one edge of said principal portion reentrantly back upon said principal portion in close relation thereto but spaced therefrom, one of said portions having a recess adapted to receive getter material which recess is covered by the other of said portions and getter material held within said recesses, said principal portion being provided with an apron substantially perpendicular to said principal portion and formed by bending said sheet member about an edge of said principal portion opposite the edge at which said tab portion is bent and in the direction of the same face thereof as faces said tab portion, and means for mounting said getter structure in said tube with said principal portion substantially perpendicular to said longitudinal axis of said tube and on the base side of said electrode unit, and with said apron toward the central axis of said tube.

ADEN J. KING.

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