US 2038513 A
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April 21, 1936. J H MANN 2,038,513 I I TUB E BASEAND SOCKET Original Filed Aug. 5, 1933 ff\ P105535 37 4 INVENTQR JULIUS HIRMANN B wwxzu,
ATTORNEY Patented Apr. 21, 1936 1 UNITED STATE TUBE BASE AND SOCKET Julius Hirmann, Hillside, N. .L, asslgnor to Radio Corporation of America, a corporation of Dela-' ware Original application August 3,
1933, Serial No.
683,434. Divided and this application March 27 1934, Serial No. 717,555
4 Claims. (01. its-32s) My invention relates to vacuum tubes and the like, and more particularly to bases and sockets for such tubes. 1
This application is a division of my correspond- 5 .ing application, Serial No. 683,434, filed August 3,
1933, and assigned to the same assignee as the; present invention.
' The conventional vacuum tube has a cupshaped base with a flat bottom on which tubular contact pins are mounted in a circle near the rim to project perpendicularly from the bottom of the base, thus adding to the overall length of the tube. These tubular contact pins are connected to the electrode elements of the tube by leading- 'in wires threaded into and soldered to the pins. The conventional socket has sprin contacts which engage the contact pinsof the base. The socket contacts extend radially outward and are fastened at theirends or intermediate their ends to the bottom of the socket by rivets or the like. The socket is inherently large .and bulky, and extends considerably beyond the outline of the base oIthe-tube. An increase in the number of contact pins on the base decreases the spacing between the pins, increases the tendency for voltage breakdown. through the base, and greatly increases the dimculty or basing the tube particularly the threading of the leading-in wiresinto the contact pins. The number of contacts which can be accommodated by the conventional socket has' likewise reached a practical limit because of lack of space and because of the increase in the tendency of voltage breakdown through the socket. Assembly of the, socket due to the number of parts required is ikewise made more dimcult.
Not only has the practical limit been reached in the numberoi contacts which. can be mounted in a conventional way in tube bases and sockets oi! conventional size, but now tube bases and sockets only about one-half the conventionalsize mustbe made with as many or even more .contacts than the bases and sockets of conventional size. The usual number of conventional contact pins cannot be mounted in the conventional way on the smaller base, yet a corresponding reduction in-size of the contact pins will result in pins which are too weak for practical use, which do not have enough contact area. and which offer very great diiliculty in the threading of the leading-in wires into-the pins. Furthermore, there is a practical limit in the reductionof the diameter of the contact pins'and of the leading-in wires, as the wires must be suiflciently large to carry the necessary it engages.
and socket than the contact pins and socket' current and also stifl! enough to' thread easily into the pins, which must, of course, have a bore somewhat largerthan the wire.
A reduction in the size of the conventional socket and its contacts will result in contacts which 5 are too weak for practical use, which do not havesuflicient contact area, and which increase the difliculty of assembling the socket. It would not be practical to materially reduce the size of. the
contacts in the socket and still have these con- 10 tacts properly cooperate with pins on the tube base which were not materially reduced from con ventional size.
The conventional contact pin is in 'eiiect riveted into the base by upsetting or spinning the inner end of the pin over the inside of the bottom of the base. The inner end is thus enlarged and in effect increases the diameter of the pin so that more room is required for spacing between the pins. As it is not feasible to reduce the diameter of thepin, the space required for fastening the. pins to thebasecannot be reduced, nor can smaller contacts be used, as the conventional socket contact is larger than the base pin which invention is to provide a base One object of my conventionalbase and socketgand yet have as many or even more contacts of ample area and properly spaced-so that .the electrical and mechanical properties of the smaller base and socket are ample to meet all requirements.
A further objector my invention is to provide a base and socket having mechanically strong contacts which are so arranged that more angular space is made available for the contacts than in the conventional base and socket and which are made to occupy less angular space on the base contacts commonly used, yet have as great-or even.
. greater contact area than the conventional pin and socket contacts.
Still another object of my invention'is to provide improved socket contacts which are simple and inexpensive to make.
' These and other objects will appear hereinafter. The novel features which I believe to be characteristic of my invention are set forth with particularity'in the appended claims, but the inven tion itself will be best underst by reference to the following specification tak in connection with the accompanying drawing in which, 'j Figure 1 shows a vacuum tube having a base made in accordance with my invention and a ntion Figure 3.
Figure is a perspective view of a socket contact made in accordance with my invention.
The vacuum tube shown in Figure 1 of the drawing has an evacuated bulb l0 enclosing the usual cathode, anode and grid or grids. The bulb ID has secured to it by cement a tubular base preferably molded from insulating material and comprising a collar ll provided with the usual indexing pin l2, and a lower portion 13 of smaller outside diameter than the collar. The portion l3 of reduced diameter has at its lower end slots l6. Flat ribbon contacts H, which extend thru, the base and ar'ewrapped longitudinally around the portion l3 of reduced diameter to provide fiat contact faces on the outside of the base, have their ends brought together in the slot IS' and welded together to fastenthe contacts in place on the base and also to form connecting lugs I 8 and I!) which facilitate and simplify the connecting of .the lead wires to base contacts l1.
when the tube is based the connecting lugs l8 and I9 practically adjoin the-outer ends of the lead wires, which extend thru the tubular portion l3 of the base shell. The ends of the lead wires are inserted between and thenwelded to-the connecting lugs l8 and I9 whereby threading of the lead wires in the tubular contact pins is eliminated, and a good electrical connection made more easily than by soldering. The contacts are hacked and supported by the base shell [3 and althoughnarrow are held sufficiently rigid to constitute a strong rigid contact.
As the width of the ribbon contact may be less than the diameter of the conventional tubular contact, and since the ribbon contacts are spaced around the exterior of the base instead of in a circle on the bottom of the base near the rim, as is done with tubularcontacts, more of such contacts may beaccommodated on a base of the usual size, or the size of the base can be materially 'reduced and-still the maximum number of contacts now feasible for the usual size base can be used. The flat contacts have ample contactarea, at least as much as the conventional contact,-and because of their bemounted on the side of the base'the tube isshortened and less head room required for it.
The flat contacts I! may to advantage be made of nickel. which is easily worked and welded.
4 They may bemade in various ways, butI prefer to cut them frommetalribbon and form them automatically by machine, as it is easier to shape the metal ribbon into a flat contact than it is to make the usual type of tubular contact.
It is obviousthat the base can be registered with the socket in various ways; for example, by
placing the contacts nonsymmetrically around the shell or providing studs or projections on the,- base shell to enter corresponding slots in the socket. I prefer to register the base and-socket by means of a stud or pin 12 for this purpose.
A socketfor the vacuum tube with the base showninrlgure 1 isshown in'Figures 1 to4 8 devices.
.size. The threading of lead wires inclusive. It comprises separate upper and lower parts which telescope and between which the socket contacts are clamped. The tubular upper part 29 of the socket has a central opening 30 large enough to receive the tube base I l and has in one side an indexing slot 3| for the stud or pin l2 on the base of the tube. This upper part 29 has a flange 32 with bosses 33 for attachingthe socket to a panel, and a shoulder. on the interior wall for limiting .the extent to which the base may be inserted in the socket.
When the base is home in the socket'the base contacts I1 are in registrywith slots 35 in the lower end of the part not the socket as mostclearly shown in Figures 3 and 4; These slots 35 extend through and to the bottom of the tubutwo parts of the socket are riveted together by v rivets 43. The bottom of thevlowe'r cup-shaped part 4| has on the inside an annular channel 7 44 in which the lower ends of the contact springs rest, and by 'which the extent of inward move- 7 ment'of the spring contact is limited. Apertures 45 in the bottom of the socket permit particles of dirt and the like to fall out of the'socket thru the bottom.- An annular collar 46 at the center of the bottom part 4| prevents foreign objects dropping into the socket far enough to short circuit'the contacts 31. It will be obvious that when the base is inserted in the socket, the base contacts II will engagethe flat part 38 of the socket contacts 31 and make a good contact of ample area. The wiping action between the contacts as the base is inserted in the-socket insuies clean contact surfaces, and .the spring 39 of the socket contact insures suflicient pressure between the contacts.
The socket contacts 31 for a socket constructed which it is now feasible to use. for the conventional base and socket can be materially increased and still have the base and socket fully meet the electrical and mechanical requirements for such In accordance with my invention I can reduce the size of the usual base and socket and still properly accommodate as many contacts as can now be used .on a base and socket of the usual into tubular contact pins has beeneliminatedthus expeditingmanufacture. The electrical connections between the cofitacts and the lead wires have been materially improved and by means of my invention I provide simple contacts which can be manufactured cheaply and easily from metal ribbon for both thebase and socket.
The embodiment of the inventiontillustrated and described herein has been selected for the purposeof setting forth the principles involved,.q but it will be apparent that various modifications maybe made to meet thedifferent conditions en counteredin'useand I, therefore, intend to cover all modifications within the scope of the appended claims. I
What'is claimed as -ne 1. A vacuum tube soc at including an annular member with an outwardly extending lip at one end, a tubular member telescoped within said annular member and formed to receive a tube base shaving contacts on its periphery and having at one end a flange for engaging said lip and having spacedslpts in the other, end said slots extending through and up into the periphery of said tubular member, and contact elements clamped between said members and extending thru said slots for providing contact surfaces on the interior of said socket, said contact elements having terminal lugs extending to the exterior of said socket between said lip and flange.
2. A vacuum tube socket including a cupshaped member having an annular lip and an annular depression on the inside bottom surface, a tubular member telescoped within said cupshaped member formed to receive a tube base having contacts on'its periphery and having a flange engaging said lip, and resilientcontacts clamped between said members and extending freely at one end thru said 'tubularmember and into said annular depression -for providing contact surfaces on'the interior of said socket to cooperate with the contacts on the tube base, said contacts having terminal lugs extending between said lip and flange-to th exterior of said socket, and means on said contacts for resiliently biasing the freely extending ends toward the center of the socket against the inside wall of said annular depression.
3. A vacuum tube socket including a cupshaped inember having an annular lip, a tubular member telescoped within said cup-shaped memher and formed to receive a tube base having con- '13 ange.
4. A vacuum tube socket including a flat bottomed cup-shaped member having an outwardly extending annular lip and an annular depression on the inside bottom surface, a tubular member telescoped within. said cup-shaped member and formed to receive a-tube base having fiat longitudinal contacts on its periphery and having at one end a flange engaging said lip and spaced longitudinal slots in the other end extending through and up into the periphery of said tubular member, resilient ribbon contacts clamped between said members and extending freely at one end thru the slots in said "tubular' member and into said depression to provide longitudinal contact surfaces on the interior of said socket to cooperate with the contacts on said tube base and having terminal lugs at the other end extend- "ing from said socket to the exterior thereof, and
means for resiliently biasing said freely extending I ends toward the center of said socket. against the inside wall of said annular depression.
' JULIUS I-HRMANN.