US2192760A - Adapter for metal radio tubes - Google Patents

Description

' March 5, 1940. H 1 THQRSQN 2,192,760

ADAPTER Fon METAL RADIO TUBES I Filed May 28. 195e Inventor'. Har-V5 l... 'Thor-son,

by Ef his tt or-nenjq.

ifi

`Patented Mar. 5, 1940 UNITED STATES PATENT OFFICE Harry L. Thorson, Schenectady, N. Y., assigner' to General Electric Company, a corporation of' New York Application May 28,

' 5 Claims.

The present invention relates to metal radio tubes and more particularly to structures for adapting tubes of this character to sockets.

In the modern type of metal radio tube7 there are a number of ways of ybringing out the leading-in conductors to the contact pins. In one case, the pins are carried by a base secured to the envelope, and ilexible conductors are connected to the pins. respect to the terminals of the given socket by means of a central projection of irregular conguration formed on the base and adapted to fit into an opening of similar co-nguration in the socket. A base of this character is termed an octal base. These bases are satisfactory in operation but have the disadvantage of being complicated in construction and of requiring considerable Work in securing the pins to the base and in connecting the conductors tothe pins.

Another method of making connection to the leading-in conductors is to provide the Contact pins as extensions of the lead-in conductors which are made stili or rigid in order to carry the pins. In this case no oase is necessary. The pins are located with respect to the terminals in the socket by making one or more oi the pins larger in diameter than the other pins, and the socket terminals which receive the larger pins are made correspondingly large. In other cases the pins are of the same size but unsymmetrically spaced about the socket. In order to inu sert the pins into the terminals, it is necessary to rotate the tube over the socket until the large pins are opposite the large openings or the unsymmetrically located pins register with their respective openings. This operation may take considerable time because it is not always possible to see the terminals so that each pin position may have to be tested for insertion. On the other hand, the octal base referred to hereinbefore does not have this disadvantage because the projection for locating the base with respect to the socket extends beyond the contact pins, and it is only necessary to align the projection with the opening in the socket.

An object of the present invention is to provide in a radio tube of the type in which the contact pins constitute leading-in conductors the advantage of the octal base by way of readily locating the tube in the socket but Without neces sitating a base. Another object is to provide a basing member for a metal tube which is readily assembled with the tube and which will alTOrd substantial protection against breakage `to the lead-in seals of the Various lead-in conductors.

These pins are located with 1938, Serial No. 210,780

(Cl. Z50-27.5)

Other objects and advantages of the adapter will be brought out in the following description and the accompanying drawing in which Fig. l is an elevational View of a metal tube provided with the improved adapter; Fig. 2 is a view looking toward the under side of the adapter as shown in Fig. l.; Fig. 3 is a cross-sectional View in part of a metal tube, the improved adapter, and socket; Fig. 4 is an enlarged cross-sectional view of a modied form of the octal projection on the adapter; Fig. 5 is a View taken at line 5-5 on Fig. 4; and Fig. 6 shows the deforming action of the pins on the sides of the openings in the adapter during the insertion of the pins; Fig. 'l is a view taken along line 'i--l in Fig. 8 showing the same opening as in Fig. 6 but with the contact pin in place; Fig. 8 is an enlarged sectional View taken along line 8-8 in Fig. 2 but showing the pin and conductor in elevation; Fig. 9 is an elevational view partly broken away of a contact pin and leading-in conductor which may be advantageously employed in connection with my invention. Fig. i0 is a fragmentary cross-sectional view of a modified form of the adapter.

Referring more particularly to Figs. 1 and 3, numeral l designates an envelope of a metal tube which terminates at the lower end in a flange 2. The tube is closed at the bottom by means of a header 3 (Fig. 3) preferably of metal and welded or otherwise secured at the periphery to the flange 2 and carrying the seals for the various leading-in conductors. These seals, for example, may consist essentially of a metal eyelet 4 flanged at the bottom and iitting snugly into openings suitably positioned in the header. These eyelets are welded or secured in any other suitable manner to the header. The envelope l may contain a plurality of electrodes, the lead ing-in conductors from which are indicated at 5. These conductors are taken through the eyelets and are insulated therefrom by means of a bead of glass 6 in a manner which is weil known in the art. The glass and metal of the eyelet 4 preferably have the same coeiiicients of thermal expansion from 0o C. up to the softening ternperature of the glass. Such glasses and metals are also Well known in the art. The header 3 is provided preferably at its center with a metal evacuating tubulation l' which is Welded or otherwise secured to the header. However, if desired, this tubulation may be taken out from any other part of the envelope. After the interior of the envelope has been evacuated, the lower end of the tubulation is pinched and welded as indin cated at 8. For making contact with the various leading-in conductors, the Contact pins B are provided which are preferably butt-welded to the conductors 5 so as to constitute an extension thereof. These conductors are made of stiff wire so as to provide the necessary support for the contact pins.

A suitable socket for a tube of this character, (Fig. 3) may comprise two plates lll of insulating material with suitable openings `for the contact pins, the opening in the lower plate (as shown) being suiciently large to accommodate hollow terminal members i2 which are well known in the art. These terminal members are provided with extensions which can be clamped between the two plates Ill, leaving a long extension or tail i3 which extends through an opening in the lower plate member lil to constitute a contact member for connection to a circuit conductor. lThe two plate portions l0 or the socket are clamped together and secured to the chassis indicated at lvl of a radio set in any suitable manner, for example, by means of bolts (not shown) which pass through the openings le.

When a tube ci the type described is employed in connection with a socket oi this character, it is customary in the prior art to have one or more contact pins 9 of larger size than the other pins and to provide socket terminals 2 sufriciently large to accommodate this pin or pins. Sometimes, the pins are all of the saine size but unsymrnetrically positioned around the base. The tube would then be rotated on top of the socket until the large pins or the unsymmetrically positioned pins had round their proper openings, after which the pins would be pressed into their respective terminals. However, in accordance with the present invention l provide adapter or basing member which eliminates much of the difficulty of finding the proper contact terminal for each pin.

This adapter consists essentially of a plate or disk l5 of insulating material such as a phenolic condensation product which is provided on one side at the periphery with lip or ilange and on the other side at the center with a large de pending cylindrical portion or projection il. The lip I6 is of sufficient depth to leave a clearance between the disk l and the lower surface or the eyelets 4. This lip abutsthe header 3 as shown. The projection il has an opening 26 therein closed at the bottom. and oi a size sui'licient to accommodate the tuliulation 'l in case the tubu` lation is provided the header end oi the envelope. As shown in 4 and 5, a inodiiied form of projection be provided with strengthening fins i which extend the entire length of the opening The projections El or 24 are provided at one side with a rectangular key portion or lug i9 which extends almost the entire length of the projection. This key may be formed integral with the member il' and constituted of the same material, or made oi metal in which c if the key is grounded, it will serve as an electrostatic shield between the oppositely positioned Contact terminals or pins. The plan View in reduced scale oi the key is shown in Fig. 2.

The adapter lll has a number of openings spaced thereabout in alignment, with the ccnducn tors 5 and or a size suiiicicnt to accommodate the pins 9. These openings are preferably provided with inwardly extending t/shaped projections or serrations shown on an scale in Figs. 6 and E. The distance between the apexes or the oppositely positioned serrations 2li is somewhat less than the diameter of the pin as indicated at 9 in Figs. 6 and 7. Consequently, when the adapter l5 is pressed over the pins, the latter are forced against the seri-ations and cause a temporary deformation of lthe material constituting the serrations during the time that the pins move through the openings in the adapter. This deforming action is illustrated in Fig. 6, which shows the inner portion of the projections El? temporarily missing. However, it has been found that after the pin has reached its nal position, the serrations tend to assume their initial position due to the resiliency of the material so that it the upper edge oi the pin is pressed beyond the upper edge of the disk i5 (Figs. 3

and 8), the serrations will spread inwardly and overlap the upper edge of the pin so as to prevent the pin from being withdrawn. This effect is shown in Figs. '7 and 8, noting that the reference character a indicates the inner edges of the serrations which have automatically resumed 'their initial shape with the contact pin in place.

The seri-ations may also take other forms than the ridge-like form illustrated. For example, one may employ circumferential rows of inwardly projecting mounds or serrations appropriately positioned to engage the upper edges of the pins when the latter are forced into the openings of the adapter.

Instead ol providing serrations within the openings in the adapter, it may be sufticient simply to provide an outwardly extending barb shown in 9 which would permit the pin i to be readily inserted in the opening in the adapter but would prevent the pin from being \vithdra.vn.. This barb could be formed, for example, by means of a chisel 22. Regardless of what expedient is employed in this connection, the adapter can be pressed tightly down over the pins 9 and retained rigidly in position. In order to insure that the adapter seats itself rrnly on the upper surface of the upper plate In? of the socket, it may be desirable to provide milled seating flanges indicated at 23 (Fig. 2) about each of the openings.

The socket lll is provided with an opening having a, keyway which ts the projection l1 and the key i9. Thus by observing the position of the keyway on. the socket and the position ol the key on the projection El, it becomes an easy matter to insert the tube into its proper position in the socket the various contact pins into their corresponding terminals. It will be noted that the projection Il and thekey i9 are considerably longer than the pins 9 so that when the combined adapter and tube are beingr located with respect to the socket, the surfaces which contact rst are the projection il' and the key IB. It is therefore no longer necessary to make one of the contact pins Q of larger diameter than the other Contact pins and to feel for the proper position of the tube with respect to the socket.

In addition to providing important advantages by way oi' readily locating the tube with respect to the socket, as explained hereinbefore. the adapter provides several other advantages. It will be noted Fig. 3 that the tight t between the pin and the opening in the adapter offers a decided restraining effect to any tendency to bend 'the pin or its conductor at this point. The lip portion lli of the adapter keeps dust particles and other foreign material from getting between the leading-in conductors and the header, which might result in low' breakdown voltages, electrical leakage, or short circuits. One outstanding advantage of the adapter is that when the socket l is secured to the chassis i4 of a radio set, the adapter keeps the header 3 from touching the chassis and thereby prevents noise in the set. It will also be noted that no extra material or parts are required to hold the adapter iirmly to the tube and that the only labor operation is to place the adapter in position on the tube.

Another form oi the improved adapter is shown in Fig. l0. The adapter is similar to that described hereinbefcre except that it is ofl larger size and is provided with an upturned ilange 28 which covers and protects the joint between the flanges E, 3.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, a discharge device provided with a metallic closure member, a plurality of conductors having portions thereof which extend through said closure member and serve as leadin connections and other portions, comprising rectilinear extensions of the i'irst portions, which project outwardly froni the closure member and serve as contact pins, a plurality or" gas-tight seals constituted of relatively fragile insulating material for supporting the said conductors from the closure member, and a base member retained in external abutting relation to said closure member, the said base member comprising a disk of insulating material ,having openings to receive the said conductors and engaging the conductors at points relatively spaced from the closure member, whereby the disk prevents lateral displacement of the conductors and consequent strain on said seals.

2. In combination, a discharge device having a generally flat metal header, a plurality of conductors having portions thereof which extend through said header and serve as lead-in connections and other portions, constituting substantially rectilinear extensions of the rst portions, which project outwardly from the header and serve as contact pins, a plurality of gas-tight seals comprising vitreous insulating material supporting the conductors from the header, a base member for providing lateral support to the conductors, the said base member having openings i'or receiving the conductors, and spacing means for maintaining the member in a fixed spaced relation to the header, whereby the member engages the conductors at points appreciably displaced from said seals.

3. In combination, a discharge device having a generally flat metal header, a plurality of conductors having portions thereof which extend through said header and serve as lead-in connections and other portions, comprising substantially rectilinear extensions of the rst portions, which project outwardly from the header and serve as contact pins, a plurality of gastght seals comprising vitreous insulating material for supporting the said conductors from the header, and a base member applied to said headerr for aiording lateral support to said conductors, the said base member having openings which are of such size as readily to receive the conductors, thereby to facilitate assembly of the discharge device and base member, but which fit the conductors with suricient snugness to maintain the discharge device and base member in permanent assembly by virtue of the frictional engagement between the base member and the conductors.

4. In combination, a discharge device containing electrode structure, a plurality of conductors having portions which extend through a Wall of the device and serve as lead-in connections for the electrode structure and other portions, comprising substantially rectilinear extensions of the first portions, which project outwardly from the discharge device and serve as contact pins, a base member constructed and arranged to provide lateral support for the said conductors, the said base member having openings which are of such size as readily to receive the conductors so as to facilitate assembly of the discharge device and the base member, and means to effect a locked engagement of the base member and the conductors upon placing the discharge device and the member in assembly.

5. In combination, a discharge device containing electrode structure, a plurality of conductors having portions which extend through a wall of the device and serve as lead-in connections for the electrode structure and other portions, comprising substantially rectilinear extensions of the first portions, which project outwardly from the discharge device and serve as contact pins, and av base member constructed and arranged to provide lateral support for the said conductors, the said base member having openings to receive the conductors, and the portions of the basev member which surround the openings being provided with deformable protuberances which permit introduction of the conductors into the openings but resist their withdrawal therefrom.

. HARRY L. THORSON.

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