US2472021A - Preassembled impedance unit - Google Patents

Description

May 31, 1949. D. H. MITCHELL PREASSEMBLED IMPEDANCE UNIT Original Filed Feb. 20, 1 942 florzald Patented May 31, 1949 "PREASSEMBLED IMPEDANCE UNIT IDonald-H. Mitchell; Chicago, Ill., .assignor to Motorola; 1110., a corporation of Illinois Original application February 20; 1942, SerialNo. 1 431,722. "Divided and this application February 21; 1945; Serial-No. 579,003

. 2 Claims.

.This: invention relates topreassembleddmpedanceunitspf the type-suitable for, usea-as; a

componentmofi an. electrical apparatus .having connection: terminals; arranged. in a; generally arcuate path; and; while itsis; of general. applica- :tion,: it: is particularly suitable for embodiment in a .nnit to belmounted: directly on. the. base; of a vacuum-tube: socket: and; is describeduherein :ln

such anapplication. This::application isiaydivision of copending application, :5 Serial 'No. 431,722,:fi-led February '20, 1942, United;.States Patent 2,439,408, and entitled Portableradio de- 'vice.

- 'Itis well'knownthat radio apparatus generally comprises a chassis 'or .framermembenaon "which are mounted a numbenoi vacumnetube sockets :iorwreceivlngr replaceablevacuum: tubes and a is also well known that the assembly of such radio apparatus is generally done by relatively unskilled employees, Which tends to aggravate all of .the'iactors discussed.

' It is anobject of the invention, therefore, to provide a new and improved.preassembledsim- :pedance unit by means of which one or. more of the above-,mentioned problems ot assembling radio cit-other electrical apparatus may. besatisiactorilysolved.

It is another object of :the-inventiontorprovide a new and improved preassembled impedance unit which permits'preassembly by automatic machinery of a substantialportion of the-circuit elements of electrical apparatus; such as resistors,

condensers and inductors comprised in the apparatus.

It is a further object of the invention to provide a new and improved preassembled impedance unit which is simple and compact and economical in construction and by means of which the lengths of the connecting conductors required in the wiring of associated electrical apparatus may be reduced to a minimum.

In accordance with the invention a preassembled impedance unit for use as a component of an electrical apparatus having connectionterminals arranged in a'generally arcuate path comprises a generally cylindrical container and aplurality of impedance elements of predetermined yalues'fixedly. arranged around the periphery-of the container and insulatedly supported thereirom and having'connection terminals extending therefrom. The connection terminals of the :unit are arranged to be disposed lu -proximity totheir respective connection terminals of-the apparatus.

For a better understanding of the invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanyingdraw-ings while itsscope will be pointed out in the appended claims.

Referrin now to the. drawings, Fig." 1': isian exploded perspective view of a preassembled/impcdance unit embodying the invention;- Fig. 2-is across-sectional view of the -,apparatus of Fig: .1; llig. 3 isa longitudinal section of the2device-of Fig.- 1 as applied to a vacuum-tube socketywhile Figs.- 4 and- 5 are top and side views, respectively, :of 'thewassembled: device of Fig. 1.

:iReierring; nowto-Figs; l and 2 of the drawings, therel-isii illustrated a preassembled' impedance unit for use as a component of, an electricalapparat. 1,1such, as a'vacuum-tube socket 94-;havinga c; dric-alr: body portionv -92 and a: plurality of connection terminals: 98' arrangedinv a generally arcuate path concentric Withthe body portion '32 and projectin fromone end: o-f-the socket. "The :impedanceiunit COnSlStS'LOfa' generally cylindrical preferably annular, open-ended container :inernber Q i of' insulationmaterial and. of chan- -.nel:-;shaped: cross section; the. open.a,:end.;thereoi being 'closed or; sealed by ayflat ringeshaped closure :member; its of: insulation material such as: fibre. Around the. periphery. :oflthe container l 0. l that is Within :the. annularrchannel thereof, are; fixedly arranged a.- .plurality .of impedance 9.816- ments such asresistors'Rland condensers C,.tvhich are of predetermined values. and electrically :connectedri together. in a predetermined circuit. arrangement to provide the desired circuit characteristics for the associated apparatus, for example a tube T1 disposed in the socket (Fig. 3). Connections I05 for connecting the resistors and condensers to the connection terminals 98 extend outwardly from the impedance unit 99 through the bottom wall thereof.

Usually not all of the connections from the impedance unit are to be connected with the socket connection terminals 98 but some of them are to be connected to other portions of associated apparatus. These other connections, therefore, are in the form of connection lugs lll5a (Figs. 4 and 5) secured to the container member Hi! to facilitate their connections With any other part of the associated apparatus. With the condensers C and resistors R in position within the container member 595, a mass of suitable impregnating insulation material, such as Wax or the like and indicated at W, is disposed in the container l M for example poured into the upper open end thereof, the hardening of the Wax embeddin the elements, retaining them in fixed positions, and protecting them against any short circuiting or exposure to the atmosphere. The closure member W3 is then glued or otherwise suitably secured tn the open end of the container llll. To facilitate the connection of the impedance unit 99 to its associated circuit elements and to indicate the mar ier in which the resistor and condenser elements are connected therein, a circuit diagram for the unit, indicated at I (Fig. is applied on the cuter periphery of the container NH.

The impedance unit 99 also includes provisions for mounting it from the cylindrical body portion of an associated electrical apparatus and concentric therewith. Specifically, its inner opening is proportioned so that it may be mounted and fitted directly on the body portion 92 of the cylindrical tube socket 9 3. As indicated in Fig. 3, the socket 94 is supported from a chassis or frame member 89 and it is adapted to receive a tube T1 and to support a cylindrical shield can Hi.

In the assembly of the impedance unit 99 on the tube socket 94, the soldering of the connections I05 with the connection terminals 98 of the socket 94 holds the impedance unit 99 in a fixed assembled position on the socket. In order to retain the impedance unit 99 in the assembly position during the soldering operation, it may be cemented or glued to the chassis 89 or to an associated element thereof. The elements within the unit 99 are so arranged that, when the unit 99 is mounted in an assembly position on the socket 94, the connection terminals I05 extending therefrom are arranged in proximity to their respective connection terminals 98 of the tube socket. With this arrangement the interconnection of the impedance unit 99 and the tube socket 94 is of maximum simplicity and the connection leads are as short as possible.

Although the impedance unit of the invention has been described with reference to a particular application thereof, it is readily apparent that it is not limited to this one application but can be constructed within the scope of this invention for use generally as a component of electrical apparatus. Considerable difficulty is usually encountered in handling and assembling of the condenser and resistor elements in a radio apparatus. By virtue of the compact and insulated assembly of the elements in the impedance unit 99, this unit can be conveniently arranged relative to any desired circuit in which it is used and connections '4 made therefrom to other portions of such circuit. Individual handling and assembling of the resistor and condenser elements and their connections into the radio circuit is thus entirely eliminated, thereby decreasing the time usually required in making the connections and providing for neater appearing and more secure electrical connections.

While there has been described What is at present considered to be the preferred embodiment of the invention, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed as new is:

1. In an electrical apparatus including one or more electron tube sockets, each of said sockets having a cylindrical body portion adapted to receive prongs of an electron tube, and a plurality of axially extending connection terminals arranged in generally concentric relation to said body portion, a preassembled impedance unit for use as a component of said apparatus comprising an annular container having an inner opening of such size as to fit closely about said body portion of a tube socket, a plurality of impedance elements of predetermined values fixedly arranged within said container and insulatedly supported thereby, and electrical conductors extending from said impedance elements out of said container, said container having an axial dimension not greater than the overall axial dimension of said tube socket body portion and said connection terminals, whereby said impedance unit may be disposed within the axial limits of and surrounding the space occupied by said socket body portion and said terminals.

2. A preassembled impedance unit as defined in claim 1, wherein certain of said electrical conductors leading from said impedance elements are arranged to be disposed in proximity to certain of the connection terminals of the tube socket with which said unit is associated, so as to facilitate electrical connection thereto.

DONALD H. MITCHELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,589,692 Hiler June 22, 1926 1,650,754 Kent Nov. 29, 1927 1,656,009 McMullin Jan. 10,1928 1,825,534 Mavrogenis Sept. 29, 1931 1,973,248 Evans Sept. 11, 1934 2,111,381 Barton Mar. 15, 1938 2,186,184 Tubbs Jan. 9, 1940 2,323,629 Smith July 6, 1943 2,377,893 Lorenzen June 12, 1945 FOREIGN PATENTS Number Country Date 573,514 France Mar. 12, 1924

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