US2014843A - Tube base and socket - Google Patents

Description

Sept. 1, W35. J. HIRMANN TUBE BASE AND SOCKET Filed Aug. '5, 1935 2 Sheets-Sheet 1 a l I ATTORNEY I Sept. 17, 1935 J HlRMANN 2,Mi,4 I

TUBE BASE AND SOCKET Filed Aug. 3, 1933 2 ShGQS-SheGt 2 Patented Sept. 17, 1935 PATENT OFFICE v TUBE BASE AND SOCKET Julius Hirmann, Hillside, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application August 3, 1933, Serial No. 683,434

3 Claims.

My invention relates to vacuum tubes and the like, and more particularly to bases and sockets for such tubes. r r a 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 spring contacts which engage the contact pins of the base. The socket contacts extend radially outward andare fastened at their ends or intermediate their ends to the bottom of the socket by rivetsor the like. Thesocketis inherently large and bulky, and extends considerably beyond the outline of the base of the tube.

Anincrease 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 greatlyincreases thedif .ficulty of basing the tube particularly the threading of the leading-in wires into the contact pins. The number of contacts which can be accommodated by the conventional socket has like- ,wise reached a practical limit because of lack of space and because of the increase in the tend- 3Q ency of voltage breakdownthrough'the socket. Assembly of the socket due to the number of parts required. islikewise mademore difficult.

Not onlyhas the practicallimit been reached in the numberof contacts which can be mounted in a conventional way intube bases and sockets of conventional size, but tubejbases and sockets only about one-half the conventional size must be made with as many or. even more contacts than the bases and sockets of conventional size.

. The usual number of conventional contact pins "cannot bevmounted 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 offerivery great difiiculty in the threading of the leading-in wires into the pins. Furthermore, there is a practical limit in the reduction of the diameter of the contact pins and of the leading-in wires, as the 50 wires must be sufficiently large to carry the necessary current and also stiff enough to thread easily into ,the pins, which must, of course, have a bore somewhat larger than the wire, A reduction, in thesize of the conventional socket andits contactswill result in contacts which sufiicient'contact area, and which increase the difiiculty of assembling the socket. It would not be practical to materially reduce the size of contacts in the socket and still have these contacts 5 properly cooperate with pins on the tube base which were not materially reduced from conventional size.

The conventional contact pin is in effect riveted into the base by upsetting or spinning the 10 inner end of the pin over the inside of the bottom of the base. i The inner end is thus enlarged and in effect increases the diameter of the pinso that more room is required for spacing between the pins. As it is not feasible to reduce the di- 15 ameter of the pins, the space required for fastening the pins to the base cannot be reduced, nor can smaller contacts be used, as the conventional socket contact is larger than the base pin which 20 it engages. a

,One object of my invention is to provide a base and socket which can be'made smaller than the conventional base and socket and yet have as many or even more contacts of ample area and properly spaced so that the electrical and me- 2 chanical properties of the smaller base and socket are ample to meet all requirements. Another object of, my invention is to provide a base so constructed'that the attachment of the leading-in, wires to the contacts is simple and 30 easier than soldering to tubular contact pins.

A further object of 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 and socket than the contact pins and V socket contacts commonly used, yet have as great or even greater contact area than the conventional pin and socket contacts.

Still anotherobject of my invention is to provideimproved base and socket contacts which are simple and inexpensive to make.

These and other objects will appear hereinafter.

i The novel features which I believe to be'characteristic ofmy invention are set forth with 'particularity in the appended claims, but the invention itself will be best understood by reference to the following specification taken in con- Figure 2 is an enlarged top view of the base shown in Figure 1 with the bulb removed.

Figure 3 is a longitudinal section of the lower end of the tube shown in Figure 1 taken along the line 33 of Figure 2.

Figure 4 is an enlarged bottom view of the base shown in Figure 1.

Figure 5 is a perspective view of a contact terminal made in accordance with my invention.

Figure 6 is a perspective view of a socket constructed in accordance with my invention and.

the tube shown in Figure l which cooperates therewith.

Figure '7 is a top view of the socket shown in Figure 6 with parts broken away to show details of construction.

Figure 8 is a longitudinal section of the socket shown in Figure 6 taken along the line 88 of Figure '7.

Figure 9 is a horizontal section of the socket shown in Figure 6 taken along the line 9-9 of Figure 8.

Figure 10 is a perspective view of a socket contact made in accordance with my invention.

The vacuum tube shown in Figure 1 of the drawings has an evacuated bulb I enclosing the usual cathode, anode, and grid or grids. The bulb III has secured to it by cement a tubular base preferably molded from insulating material and comprising a collar provided with the usual indexing pin I2, and a lower portion I3 of smaller outside diameter and smaller inside diameter than the collar for providing an inside shoulder I4. In the particular device shown in Figures 1, 2, 3, and 4, the base is provided with apertures I which extend through the base from the interior of the base at the top of the shoulder M to the exterior of the base at the lower end of the collar The portion I3 of reduced diameter has at its lower end slots I6 directly in line with the apertures I5. Flat ribbon contacts extend through the apertures l5 and slots l6 and are wrapped longitudinally around the portion |3 of reduced diameter as shown to provide flat contact faces on the outside of the base. The ends of the ribbon contacts are brought together and welded to fasten the contacts in place on the base and also to form connecting lugs I8 and I9 which facilitate and simplify the connecting of the lead wires 20 to the base contacts ll.

When the tube is based the connecting lugs I8 and I9 practically adjoin the outer ends of the lead Wires 20, whichextend through the tubular portion I3 of the base shell. The ends of the lead wires are inserted between and then welded to the connecting lugs I8 and I9, whereby threading of the lead wires into tubular contact pins is eliminated, and a good electrical connection made more easily than by soldering. The contacts are backed and supported by the base shell I3 and although narrow are held sufliciently 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 tubular contacts, more of such contacts may be accommodated 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 contact area, at least as much as the conventional contact, and because of their being mount- 4 ed on the side of the base the tube is shortened and less head room required for it.

The flat contacts I i may to advantage be made 5 of nickel which is easily worked and welded. They may be made in various ways, but I prefer to cut them from metal ribbon 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 obvious that the base can be registered with the socket in various ways; for example, by placing the contacts nonsymmetrioally 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 I2 for this purpose.

A socket for the vacuum tube with the base shown in Figures 1 to 4 inclusive is shown in Figures 6 to 9 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 3|! large enough to receive the tube base H 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 attaching the socket to a panel, and a shoulder 34 on the interior wall for limiting the extent to which the base may be inserted in the socket.

When the base is home in thesocket the base contacts I! are in registry with slots35 in the lower end of the part 29 of the socket as most clearly shown in Figures 8 and 9. Spring contacts 3! project through these slots and have flat portions 38 which are resiliently forced into engagement with the base contacts by spring portions 39. Connections to the contacts are 40 made by connecting lugs 40 on the socket contacts.

The contacts 31 are held in place by being clamped between the upper part 29 grooved to receive the contacts and the lower cup-shaped part 4| of the socket, which has a lip 42 to cooperate with the flange 32 of the upper part. The two parts of the socket are riveted together by rivets 43. The bottom of the lower cup-shaped part 4| has on the inside an annular channel 44 in which the lower ends of the contact springs rest, and by which the extent of inward movement 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 through 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. 0

It will be obvious that when the base is in- 6 serted in the socket, the base contacts I! will engage the 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 insures clean contact surfaces, and the spring 39 of the socket contact insures sufficient pressure between the contacts. The socket contacts 31 for a socket constructed in accordance with my invention can be made in s much the same way as the base contacts I1. I

It will be seen that I have provided a base and socket in which the maximum number of contacts which it is now feasible to use for the conventionalbase and socket can be materially increased and still have the base and socket fully means of my invention I provide simple-contacts which can be manufactured cheaply and easily from metal ribbon for both the base and socket. [The embodiment of the invention illustrated and described herein has been selected for the purpose of setting forth the principles involved, but it will be apparent that various modifications may be made to meet the different. conditions encountered in use and I, therefore, intend to cover all modifications within the scope of the appended claims.

What is claimed as new is,--- V 1. A vacuum tube base including a tubular member having at one end a collar of larger diameter than the rest of the member and spaced slots in the other end, said tubular member having apertures spaced around its periphery intermediate its ends and in line with said slots, and ribbon contacts extended through said apertures and said slots and longitudinally wrapped around said base between said apertures and said slots to provide fiat contact surfaces and to space said contacts around said tubular member, each of said contacts having its ends fastened together to secure the contact to said tubular member and to provide lugs between which a lead wire is attached to the contact.

2. A vacuum tube base including a tubular 5 member having apertures spaced around its periphery intermediate its ends and spaced slots in one end in line with said apertures and U-shaped ribbon contacts extended through said apertures and said slots and longitudinally Wrapped around said tubular member between said apertures and said slots to provide external fiat contact surfaces and to space said contacts around said tubular member, each of said contacts having its ends fastened together adjacent the slots to secure the contact to said tubular member and to provide lugs at the inner surface'of the tubular member to which a leadwire is attached.

3. A vacuum tube base including a tubular member having a shoulder on the interior thereof, said member having spaced apertures extending through said member at said shoulder and having slots in one end thereof in line with said apertures, and U-shaped ribbon contacts extended through said apertures over said shoulder and wrapped around said member to lie fiat against said member with the ends of said contacts extended through and fastened together adjacent said slots to secure said contacts in position around said member and to provide lugs at the inner surface of said tubular member.

JULIUS HIRMAN N.

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