US2529502A

US2529502A - Tube socket

Info

Publication number: US2529502A
Application number: US29865A
Authority: US
Inventors: William I Kelly; John R Livingood
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-05-28
Filing date: 1948-05-28
Publication date: 1950-11-14
Anticipated expiration: 1967-11-14

Description

Nov. 14, 1950 w. 1. KELLY ET AL TUBE SOCKET Original Filed Nov. 10, 1943 FIG. 4

INVENTOR JOHN RLIVINGOOD a WILLIAM LKELLY Hffornj Patented Nov. 14, 1950 TUBE SOCKET William I. Kelly, Quakertown, Pa and John. R; Livingood, White Plains, N. Y., assignors tothe United States of America as. represented by the Secretary of War Continuation. of application Serial. No; 509,674,

This; application; May 28, 1948, Serial No. 29,865

2 Claims- (Cl. 173 -328) (Granted under the act of March 3', 1883, as amended April 30, 1928; 370 O.'G. 757) November 1943.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

The present application is a continuation of our pending application, Serial Number 509,674, filed on November 10, 1943, now abandoned.

This invention relates to sockets for electron tubes, and particularly to a novel design of such sockets to prevent shock injury to the electron tubes.

A conventional electron tube with a glass envelope has a plurality of electrode terminals or pins protruding therefrom. It is common practice to bring these terminals, or a majority of them, out at the base of the envelope and to i'nsort them in a more or less rigid socket, each terminal or pin fitting into an individual insert or pinclip of said socket. The individual insert provides the proper contact for a particular electrode terminal, and the tube is physically supported by the electrode terminalswhich are inserted in thesocket.

The electrode terminals or pins of such tubes are sealed in the glass at the base of the tube, and any pressure on them sets up strains in th glass envelope. We have found that such strains are caused by forces applied on the tube by inserting or-removingv thepins from the sockets, or bysubjecting the tubes to vibration or shock when properly mounted in such sockets. Tube breakage, caused by the above-described strains, has beenthe source of considerable failure in electrical circuits, particularly in portable and. vehicular radio sets.

It is an object of our invention to furnish a tube socket which will eliminate; or reduce the strain:

producing forces on: the glass-envelope when'the. tube-is subjected to a maximum amountr'of excursion For a better understanding: of our invention together with further objects, reference is .hadi

in'the. following. description to: the: accompanying drawings Figure 1 is a perspective view of ourrinvention assembled: and ready: for: use

Figure 2 is a perspective ViHWi oiour invention with' the: excursion limiter; and. a, socket: or: base:

2 portion shown separately beforebeing assembled together;

Figure 3 is'atop view of the socket of Figure 1; Figure 3A is an enlarged fragmentary view of.

one of the pin clips of Figure 3, in position inv the socket;

Figure 4 is a sectional view of the socket taken alongline 4-4 of Figure 3 and Figure 5 is an elevational view of an individual.

pin clip.

Referring to the figures, inwhich like numbers refer to like elements, the excursion limiter I is. higher than conventional shield bases, being inch high in a preferred embodiment of our'invention as adapted to a miniature seven pin tube. This excursion limiter I is fastened to socket or base portion 2 by crimping the lower edge 3 of the excursion limiter under the shoulder 4 of said socket portion 2. Outwardly extending protuberances 5 on the excursion limiter I are provided for the purpose of attaching a conventional electrical shield thereto. Notch 6 in the top of the excursion limiter I facilitates the orientation of a.

ing material provided with proper cavities I, re-

ceivable to individual pin clips 8. A socket portion 2 for use with the smaller, high frequency tubes may be provided with a tube 9 of conductive material extending through a hole I [I at the center of the socket portion 2 to furnish electrical shielding between the electrode terminals.

As illustrated in Figures 3A and 4, each cavity 1 is sufiici'ently large so that an individual pinclip 8 fits loosely therein, allowing both expansion of said pin clip on receiving a tube pin without being restricted by cavity I and a certain amountof free excursion within said cavity. This permits a maximum amount of tube excursion before strain-producing forces are transmitted through the pin to the glass envelope of the tube. on assembly, as illustrated by Figure 4, each individual pin clip 8 is inserted from the top of cavity I, terminal end I I first, and is-crimped below the bottom of the socket portion 2 therein. I

to retain it loosely As shown in Figure 5, each individual pin clip 8 is shaped from a unitary strip of resilient metal having identical notches cut into opposing sides in the central portion [8 thereof. The upper edge of the strip is indented longitudinally in the form of a U, as at l (see Figure 5), and the sides of the upper portion of the strip are bent into a generally cylindrical shape with the head of the cylinder l6 being warped into the form of lips ll, of lesser inside diameter than the balance of said cylinder, so as to securely clamp an inserted pin of a vacuum tube. The lower edge of the strip is rounded and a slot iscutinto the lower portion to enable the soldering of a connecting lead thereto.

As shown in Figure 4, each cavity 1 extending through socket or base portion 2 comprises an upper cup portion 26, which is substantially D- shaped in horizontal cross section (as shown in Figures 3 and 3A), and a slot 22 communicating between the cup portion and the lower surface of socket portion 2, said slot 22 being a straight line in horizontal cross section and in register with the fiat surface 24 of the said D-shaped cup portion. When a pin clip 8 is inserted into cavity 1, the cylindrical portion !5 is contained loosely within the cup portion 23 while thenotched central portion N3 of pin clip 8 and the upper part of the terminal portion II are received within the slot 20, thereby allowing the lower part of the terminal portion l l of the pin clip 8 to extend below the under surface of the socket portion 2.- It; will be readily seen that in assembly the insertion of pin clip 8 into cavity 1 is easily accomplished without any forcing action.

A high center [2 is. provided on the socket portion '2 to support an electron tube, at its base and thereby prevent the pins of the tube from being inserted completely within the socket portion 2; The high center I2 also allows a tube to rock when subjected to vibrations and shocks and when it is being removed from a socket, as for replacement. Allowance is made for the pins to make good contact with the pin clips 8, but since they are restricted from being completely inserted within the socket portion 2, any tube excursion will be accompanied by less strain-producing force on the glass envelope. This is due to the increased lever arm between the tube envelope and the point where the pin is fastened to the pin clip 8. Heretofore, in standard tube sock ets, the tube pins were inserted in rigid pin clips or through very small holes. Any shock or vibration of the tube socket thus caused the vibration or shock to be transmitted to the glass envelope of the tube. However, in our particular invention there is no such rigidity or'restriction. The pin clips 8 are loosely fitted in cavities 1. Each tube pin is electrically connected to its pin clip 8 only at the inner peripheral surface of the lips i? thereof. Thus any vibration or shock to the tube base will not be transmitted through the glass envelope as readily as in the structures heretofore mentioned, in which the tube pins were rigidly connected to a base socket. Further, each pin clip of the present improved socket is free to adjust its position to the tube pin being inserted as it is free to move laterally in the cavity l and it can pivot to a predetermined extent about the inner peripheral surface of the lips H, the inner diameter of the cylinder it being greater than the outer diameter of the tube pin, except at the said lips H, as already pointed out.

In the socket just described, the excursion Lil 4 limiter I and shield (not shown) are preferably of metal so as to act as an electrical shield. In addition however, the excursion limiter I should be high enough, and have an inside diameter of such size that it will allow a vacuum tube a certain amount of lateral excursion, but will prevent any excursion beyond safe predetermined limits.

As already explained above, the present socket is so designed that each of the pins of a vacuum tube is able to pivot relative to the pin clip 8 into which it is inserted and each of said pin clips 8 is able to float relative to the socket portion 2. Hence a vacuum tube is free to undergo a certain amount of lateral excursion when subjected to shocks or vibrations. Such lateral excursion is further encouraged by the high center I2 of the socket portion 2, as it keeps the pins of a tube from being inserted too far into the pin clips 8 and it also acts as a fulcrum about which the tube may rock.

This lateral excursion is desirable asit helps to absorb shocks and vibrations which otherwise would be transmitted to and injure the glass envelope and/or the internal structure of a tube. It will be appreciated however that, if the tube pins are pivoted beyond the point allowed by the design of the pin clips 8 and socket portion 2, said pins will be bent and/or the glass envelope will be strained. The excursion limiter I is therefore incorporated in the present socket to define limits within which lateral excursion is safe and desirable, but beyond which such excursion would be likely to damage a tube.

Obviously, for the purpose aforesaid, the diameter of an excursion limiter I will depend upon its height; the greater the height the greater the permissible inside diameter. How-1 ever, as tubes are inserted and withdrawn by: hand, a certain amount of a tube should extend beyond the excursion limiter. Tests have dic-. tated that an excursion limiter of about 4-inch is satisfactory for conventional miniature tubes.

We have shown a combination of improve v ments in a tube socket, which will allow a desirable excursion of an electron tube, but which will keep such excursion within safe limits and thereby will materially reduce strain on the glassenvelope thereof, when said electron tube is mounted in said tube socket. Tests have shown that this combination eifects a substantial reduction in breakage of electron tubes by shock and vibration and in damage sometimes resulting when a tube is inserted or withdrawn from a socket.

Although we have shown and described aspecific embodiment of our invention, we are fully aware that many modifications thereof are possible. Our invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

We claim: 1. In an electron tube socket having a base portion of insulating material, said base portion pro vided with a plurality of cavities including a like plurality of resilient pin clips, said pin clips each" having an upper portion adapted to securely re sioned so as to loosely contain the constrictedportion of said clips, the combination of means comprising a high center on said socket portion for fixing the extent to which a tube may be inserted into said socket and about which a tube may be rocked, limiter means for limiting the amount of rocking of a tube about said high center after its insertion into said clips, and wherein the excursion limiter consists of a tubular member fixed to the base, and extending upwardly therefrom, said tubular member having an inner diameter larger than the upper diameter of the electron tube surrounded by the tubular member, the difference in the said diameters permitting a predetermined limit of lateral excursion of an electron tube operably positioned in said socket.

2. In an electron tube socket the combination of an insulating base portion provided with a plurality of cavities, a plurality of resilient pin clips adapted to securely receive the pins of a tube, said clips having a constricted central portion, and a pin-gripping top portion, said cavities having an upper cup portion dimensioned so as to loosely contain the cylindrical portions and a narrow lower portion dimensioned to loosely contain the constricted portion of said clip whereby a tube operably positioned in said socket may rock, a raised portion in the center of said base portion to provide a fulcrum about which said tube may rock; and means for limiting the extent to which a tube may be rocked while positioned in said socket, said last-named means comprising REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,628,001 Schur May 10, 1927 1,767,139 Kirby June 24, 1930 1,767,690 Meuer et a1 June 24, 1930 1,771,094 MacFadden July 22, 1930 1,788,066 Reynders Jan. 6, 1931 2,269,605 Smith Jan. 13, 1942 2,398,626 Del Camp Apr. 16, 1946 2,444,048 Keller June 29, 1948 FOREIGN PATENTS Number Country Date 559,579 Great Britain Feb. 24, 1944