US2859311A - Electrical switch - Google Patents

Description

Nov. 4, 1958 a w'CoNcELMA-N 2,859,311 ELECTRICAL SWITCH I 2 Sheets-Sheet 1 Original Filed Nov. 16. 1953 Nov. 4, 1958 c. w. CONCELMAN ELECTRICAL SWITCH Original Filed Nov. 16. 1953 2 Sheets-Sheet 2 United States Patent ELECTRICAL SWITCH Carl Concelman, Danbury, Conn., assignor, by mesne ass gnments, to Amphenol Electronics Corporation, Chicago, 111., a corporation of Illinois Continuation of application Serial No. 392,237, November 16, 1953. This application October 31, 1955, Serial No. 543,785

4 Claims. (Cl. 200-153) General This invention relates to electrical switches of the type which selectively connects a first high-frequency wavesignal coaxial transmission line to any of a plurality of such lines.

This application is a continuation-in-whole of applicants application Serial No. 392,237, filed November 16, 1953, entitled Electrical Switch.

One prior type of electrical switch for selectively interconnecting coaxial transmission lines utilizes a single relayactuated spring blade pivotally mounted at one end thereof which is fixedly and conductively attached to the inner conductor of a first transmission line. The other end of .the switch arm is displaceable between closely spaced inner conductors of a pair of transmission lines for selectively connecting the individual inner conductors thereof to the inner conductor of the first transmission line. While a switch of this type has desirable characteristics, it has the limitation in certain applications that an unterminated inner conductor extends into the high-frequency energy field and, thus, picks up so-called cross-talk signal energy. Moreover, the voltage standing-wave ratio developed by this type of switch may beundesirably high for some applications. Various rotary switches have also been proposed, but in general these may be more expensive to manufacture than is desirable for some applications.

lt is an object of the present invention, therefore, to provide a new and improved electrical switch of the type described which avoids one or more of the above-mentioned limitations of prior switches of this type.

It is another object of the invention to provide a new and improved electrical switch of simple and inexpensive construction for selectively connecting -a first high-fiequency wave-signal coaxial transmission line to any of a plurality of such lines.

, It is another object of the invention to provide a new and improved electrical switch of the type described adapted for use in the high-frequency range and which may be readily constructed largely by screw-machine operations. -It is another object of the invention to provide a-new and improvedelectrical switch of the type described which is of simple construction adapted for use in the high frequency range and which resultsin reduced cross talk. ,In'accordance with a particular form of the invention, an electrical switch for selectively connecting a first highfrequency wave-signal coaxial transmission line to any of a plurality of such lines. comprises a support having a chamber defined by conductive walls. The switch includes a first coaxial connector for connection to the first transmission line and having an outer conductor conductively connected to the chamber walls and having an inner con-' ductor extending into the chamber. The switch also includes a plurality of coaxial connectors for individual connection; to the plurality of transmission lines having outer conductors conductively connected to the chamber walls and having inner conductors. The switch also includes apluralityof movable conductive switch arms;

Patented Nov. 4, 1958 individually conductively connected to the inner conductors of the plurality of connectors and extending within the chamber radially to the inner conductor of the first connector and the axes of the plurality of switch arms being substantially along a common surface substantially perpendicular to the inner conductor of the first 'connector for selectively conductively connecting the individual inner conductors of the plurality of connectors to the inner conductor of the first connector or to the chamber walls. The switch also includes actuating means for selectively operating the switch arms.

For a better understanding of the present invention, together with other and further objectsthereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims. Referring to the drawings: Fig. 1 is an elevational view, partly in section, of an electrical switch constructed in accordance with a particular form of the invention;

Fig. 2 is an end elevational view of the switch as along the line 22 of Fig. 1; Fig. 3 is an elevational view of a modified electrical switch constructed in accordance with the invention;

Fig. 4 is a sectional view of the Fig. 3 switch as seen along the line 44 of Fig. 3, and y I Fig. 5 is a sectional view of the Fig. 3 switch as seenalong the line 5-5 of Fig. 4.

Description of Fig. 1 electrical switch Referring now more particularly to Fig. 1, 'there, is, represented an elevational view, partly in section, of an electrical switch 10 constructed in accordance with the invention for selectively, connecting a first high-frequency wave-signal coaxial transmission line to any of a plurality of such lines. The switch 10 includes a support llhaving a chamber 12 which may, for example, be of substanitally; uniform, square cross section and preferably is substan: tially less than one-half wave length long over the oper; ating frequency range of the switch 10. The chamber 12' is defined by conductive Walls including wall 13, as shown in the drawings. The support 11 may be constructedof any suitable material such as brass which may then be silver plated. a

A plurality of coaxial connectors are electrically coupled to chamber 12. These connectors provide individual connection to transmission lines and having outer conductors conductively connected to the chamber walls and inner conductors which preferably extend into the chamber. More particularly, a pair of like cylindrical connectors 14 and 15 of predetermined diameter are, for example, disposed along a predetermined longitudinal axis of the chamber and have outer conductors 16' and 17, respectively, conductively connected to and elfecti vely" tangential to the chamber walls at opposite ends of the chamber 12. By effectively tangential" is meant that: the outer cross-sectional dimensions of the chamber 12' preferably are approximately equal to the inner diameter: of the outer conductors of the connectors 14 and 15L Inner conductors 18 and 19 of the connectors 14 and 15 preferably are spaced from the respective outer con}:

- ductors thereof by suitable bodies of dielectric material W axis extending into the support 11 along the 'a'xislof t 18a and 19a extending into the chamber 12 and fixedly" disposed Within the outer conductors 16 and 17. The connectors 14 and 15 may be of any suitable type and may, for example, comprise connectors of the type described and claimed in Patent 2,540,0l2-Salati, entitled Elecconnector 15. Referring again to Fig. 1, the connector 20 preferably is disposed approximately midway between the pair of connectors 14 and and has an inner conductor 21' which preferably extends into the'cha'm'ber Hand is supported within the connector by a body of suitable dielectric material 22 fixedly disposed in a stepped bore 13zz in the support 11.

A pair of movable conductive switch arms 23 and 24, preferably of resilient material, such as beryllium copper, are individually conductively connected and secured to the inner conductors 18 and 19 of the connectors 14 and 15, respectively, by any suitable means such as soldering. The arms 23 and 24 preferably are seated in suitable slots in the inner conductors 18, 19 and dielectric spacers 18a, 19a, respectively, to provide a rigid mechanical support for the arms. The arms 23 and 24 preferably extend within the chamber to the inner conductor 21 of the connector on opposite sides thereof for selectively conductively connecting the individual inner conductors 18 and 19 of the connectors 14 and 15 to the inner conductor 21 of the connector 20 or to the chamber wall 13. Suitable contact points 25 and 26 are attached to the ends of the switch arms 23 and 24, respectively, for effecting the desired contact between the respective switch arms and the inner conductor 21 or the chamber wall.

As will be more fully explained hereinafter, the arms 23 and 24 are shown under stress with the arm 24 conductively connected to the inner conductor 21 of the connector 20 and the other arm 23 preferably conductively connected to an adjustable conductive contact screw 27 in the support 11 for effecting a conductive connection to the chamber wall 13. The arm 24 preferably is conductively connected 'in the absence of stress thereon to anadjustable conductive contact screw 28 in the support 11 and the other arm 23 preferably is conductively connected in the absence of stress thereon to the inner conductor 21 of the connector 20.

The switch 10 also includes actuating means for selectively effecting conductive connection of one ofthe arms 23, 24 to the inner conductor 21 of the connector 20 or to the chamber wall 13 and the other arm to the chamber wall 13 or to the inner conductor 21 of the connector 20,respectively. The actuating means comprises, for example, a pair of cylindrical dielectric members 29 and 30 extending through apertures in the wall 13 into the chamber 12 and slidably disposed normal to the arms 23 and 24, respectively, for deforming the arms in one position thereof, shown in the drawings, selectively to effect conductive connection of the arm 24 under stress to the inner conductor 21 of the connector 20 and the other arm 23 under stress to the chamber wall 13.

i There preferably is also provided control means comprising an elongated cam-operated spring-mounted member 31 for simultaneously displacing the dielectric members 29 and 30 to effect the switching operation. As represented in Fig. 2, the member 31 is attached by means of a spring 32 to a mounting bracket 33 for the switch 10. A slidably displaceable cam 34, as indicated by the arrows, is mounted on the bracket 33 and operatively connected to a push-pull switch button 35, as indicated by a broken line 36.

From the foregoing description, it will be seen that the various apertures in the support 11 may be formed quickly and conveniently by inexpensive screw-machining operations. The outer conductors of the connectors 14, 15, and 20 may be made in a similar manner and the inner conductors thereof may then be assembled and held in a spaced coaxial relation with the respective outer conductors b'y insulators. The switch arms 23 and 24 may be "fabricated by simple stamping operations. After the switch is assembled, a suitable cover 37, represented in Fig. 2,"may be utilized to complete the switch housing. Thus, the manufactureof the switch 10 lends itself to mass production techniques and the cost thereof is relatively low.

Referring to Fig. 2, when the switch button 35 is in the position shown in the drawings, the cam 34 supports the member 31 in the position shown which, in turn, maintains the dielectric actuating members 29 and 30 in the position represented in Fig. .1. In this operating condition, the inner conductor 19 of the connector 15, which may, for example, serve as an output connector, is connected by the switch arm 24 to the inner conductor 21 of the connector 20 which may, for example, supply input-signal energy to the switch. The inner conductor 18 of the other connector 14, which may, for example, also be an output connector, is connected to the chamber wall 13 through the screw 27 which may be adjusted for desired contact pressure. The switch arms 23 and 24 effect the respective connections just described under stress exerted thereon by the dielectric members 29 and 30, respectively.

When the switch button 35 of Fig. 2 is pushed "toward the mounting bracket 33, cam 34 moves into a position which allows the member 31 to spring away from the support 11 as a result of the resiliency of the spring 32. The resilient switch arms 23 and 24 then spring into contact with the inner conductor 21 and the screw 28, respectively, and displace the dielectric members 29 and 30 accordingly.

Since there is provided a conductive connection between the chamber wall 13 and the inner conductor of the connector 14 or 15 which is disconnected from the inner conductor 21 of the connector 20, the energy pickup resulting from capacitive coupling of the dis connected connector is substantially reduced. This res'ults'in reduced cross talk between the input connector 20 and the output connector 14 or 15 disconnected there: from.

It is well known that the characteristic impedance of a high-frequency wave-signal coaxial transmission line is a function of the ratio of the inner diameter of the outer conductor of the transmission line and the outer diameter of the inner conductor thereof. Similar considerations apply to the characteristic impedance of the transmission line effectively formed by the conductive walls of the chamber 12 and the switch arm 23 or 24.

Accordingly, the cross-sectional dimensions of the chamber maybe approximately equal to the diameter of the outer conductors of the connectors 14, 15, and 20.- The dimensions of the switch arms 23 and 24may'then be selected approximately to provide a desired characteristicimpedance for the transmission line eifectively formed by the chamber walls and the switch arm 23 or-24.

By proportiom'ng the length of each half of the chamber 12 to be substantially less than one-quarter wave length over the operating range of the switch 10, impedance discontinuities within the effective transmission line formed by the chamber 12 and switch arms 23, 24

can be conveniently proportioned approximately toca n c'el each other over the operating range. For example, the increase of capacity introduced into the transmission line by the extension of the dielectric spacer 18a into the chamber 12 may be approximately canceled by the reduction'of capacity present in the region surrounding the inner conductor 21 due to recesses in the chamber walls provided by bore 13a. Above the normal operating range of the switch 10, as the electrical spacing between the above-mentioned discontinuities approvided between the transmission line connected to the connector 20 and the transmission line connected to either of the connectors 14 and 15. In this manner, a relatively low voltage standing-wave ratio may result for the switch 10.

While applicant does not wish to be limited to any particular dimensions, the following approximate dimensions have been employed in a switch constructed in accordance with the invention for use at signal frequencies in the range of 100-to 1000 megacycles:

Length of support 11 inches 2 Width and height of chamber 12 do A Length of switch arms 23, 24 do Width of switch arms 23, 24 do .200 Thickness of switch arms 23, 24 ...do .008 Spacing between conductor 21 and dielectric membBI'S 29, 30 inches /8 Extension of conductor 21 into chamber 12 w inches-.. 11/64 Diameter of conductor 21 do .084 Nominal characteristic impedance of efiective transmission line of chamber- 12 and switch arms 23, 2 ohms 50 Description ofFig. 3 electrical switch Referring now to Fig. 3, there is represented an elevation'al view of a modified electrical switch 50 constructed in accordance with the invention and generally similar to the switch-represented in Figs. 1 and 2. As represented in Fig. 4, which is a sectional view of the switch 50 taken along the line 4-4 of Fig. 3, the switch 50 includes a' support 51. preferably having a pair of elongated, substantially parallel and longitudinally aligned chambers 52, 53 defined by the conductive walls of the support 51 and a suitable conductive member 54 which separates the chambers within the switch 50.

Twopairs of coaxial connectors 56, 57 and 58,59

which may, for example, be output connectors, preferably have outer conductors conductively connected to the walls of the individual chambers adjacent the ends thereof A coaxial connector 60 serving, for example, as an input connector preferably has an outer conductor 61 conductively connected to the walls of one of the chambers approximately at the mid-point thereof and has an inner conductor 62 extending into both of the chambers52and 53 through a. suitable bore 63 in the member 54. t V f Two pairs of movable conductive switch arms, preferably comprising resilient leaf springs 64, 65 and 66, 67, are conductively connected to the inner conductors of the corresponding connectors 56, 57 and 58, 59, respectiyely, and preferably are conductively connected in the absence-of stress thereon chamber walls, as, representedin Fig; 5, which is a sectional view of the switch 50 taken along the line 5-5 of Fig. 4.

Two pairs of elongated dielectric actuating members 68, 69 and 70, 71 preferably extend through the chamber walls into the individual chambers and may, for example, be individually slidably disposed approximately normal to the arms 64, 65 and 66, 67, respectively, for deforming the arms selectively to eifect conductive connection of one of the arms under stress to the inner conductor 62 of the connector 60 and the other arms to the chamber walls. There preferably is also provided control means for successively displacing the dielectric members to effect the switching operation. This control means comprises, for example, arms 72 and 73, represented in Fig. 4, responsive to energization of solenoid relays 74 and 75, respectively, for displacing the dielectric actuating members 68 and 71, respectively. Similar solenoid relays, such as the relay 76 of Fig. 3 and another relay (not shown), may be provided to control the displacement of the dielectric members 69 and 70.

Operation of.Fig. 3'electrical switch The operation of the, switch 50, represented in Figs. 3, 4, and 5, may be best understood by referring to Figs; 4 and 5. When the solenoid relays individually controlling the switching operation are de-energized, the corresponding switch elements, such as 64 and 65, are conductively connected to the chamber walls in their nor-' mal positions, as represented in Fig. 5. When one of the relays, such as the relay 74 of Fig.4, is energized, the relay arm 72 exerts a force which displaces the dielectric member 68, causing the switch arm 64 to con tact the inner conductor 62 of the connector 60. In this operating condition, the output connector 56 is actively connected to the input connector60 while the remaining connectors have inner conductors which are conductively connected to the chamber walls and, thus, are effectively disconnected from the input connector. z

By means of a'suitable electrical switch, not shown, which controls the energization of the solenoid relays, any selected output connector may be connected to the input connector 60 while the remaining connectors are eifectively disconnected therefrom. It will also be understood that any suitable number of chambers andoutput connectors may be aligned, with the chambers 52 and 53 to form, for example, ,a fiveor six-position switch. These'chambers. may individually be proportioned ina manner similar to the'chamber 12 of the Fig. 1 switch.

From the foregoing description, it will be apparent that a switch constructed in accordance with the inven-' tion has the advantage of being simple in construction and inexpensive to manufacture. The switch has the additional advantage of providing reduced undesired cross talk between input and output connectors thereof. The switch also provides satisfactory.standing-wave ratios in, for example, the to 1000 megacycle range.

While there have been described what are at present considered to be the preferred embodiments .of this invention, it will obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and-it is, therefore, aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. An electrical switchfor conductively connecting a first high-frequency wavesignal coaxial transmission line to any one of a plurality of such lines comprising, 'a switch support having an internal and substantially hollow chamber extending longitudinally between interior conductive end walls, said chamber having a substantially uniform cross-section defined by confronting pairs of parallel and interior conductive walls, a first coaxial con nector electrically coupled to said chamber intermediate the end walls thereof and adapted for connection with the first of said transmission lines, said connector having an outer conductor conductively connected to said chamber walls and an inner conductor extending into said chamber and terminating therein wherein the axis of said connector in the region where it eifects electrical coupling to said chamber is substantially perpendicular to the longitudinal dimension of said chamber, a coaxial connector electrically coupled to said chamber on each side of said first connector 'and defining a plurality of connectors for individual connection to respective ones of said plurality of transmission lines, said plurality of connectors each having an outer conductor conductively connected to said chamber walls and an inner conductor terminating in said chamber, a plurality of movable conductive switch arms having a substantially uniform crosssection defined by opposed pairs of parallel surfaces, said arms extending substantially longitudinal-wise in said chamber for movement from one to another of two positions wherein said first connector is alternately connected to and disconnected from respective ones of said plurality of connectors, each arm having oneend conductively connected to and supported -from a'respective one of the inner conductors of said plurality and having a free end adapted for conductive connection with the inner con ductor of said-first Connector, wherein each arm and the coextending chamber walls surrounding same serve as a section of coaxial line coupling said first connector with a respective one of the plurality of connectors when the correlated arm is positioned to effect conductive connection with the inner conductor of said first connector. An electrical switch for conductively connecting a first high-frequency wave-signal coaxial transmission line to'any one of a plurality of such lines comprising, 'a switch support having an internal and substantially hollow chamber extending longitudinally between interior conductive-end walls, said chamber having a substantially uniform cross-section defined by confronting pairs of parallel and interior conductive walls, a first coaxial connector electrically coupled to said chamber intermediate the end walls thereofand adapted for connection with the first of said transmission lines, said connector having an outer conductor conductively connected to said chamber walls and an inner conductor extending into said chamber and terminating therein wherein the axis of said connector in the region where it effects electrical coupling to said chamber is substantially perpendicular to the longitudinal dimension of said chamber, a' coaxial connector electrically coupled to said chamber on each side of said first connector and defining a plurality of connectors forindividual connection to respective ones of said plurality of transmission lines, said plurality of connectors each having an outer conductor conductively connected to said chamber Wallsand an inner conductor terminating in said chamber, a plurality of movable conductive switch arms having a substantially uniform cross-section definedby opposed pairs of parallel surfaces, said arms extending substantially longitudinalwise in said chamber for movement from one to another of, two positions wherein said first connector is alternately connected to and disconnected from respective ones of said plurality of connectors, each arm having one end conductively connected to and supported from 2. respective one of the inner conductors of said plurality and having a free end adapted for conductive connection with the inner conductor of saidfirst connector, movement of an arm to a first of its positions causes the free end thereof to contact conductively with a chamber wall juxtaposed the first inner conductor, movement of an arm to the second of itspositions causes the freeend thereof to contact conductively with'the innerconductorof said first connector wherein such arm and the coextending chamberwalls surrounding same serve as-a section of coaxial line coupling said first connector with the correlated connector of said plurality.

3. Apparatus ase defined in claim 2, wherein-the crossnected to said chamber walls, said connector also having an inner conductor extending through a first of said chambers and "extending into and terminating Within a second "ofsaid chambers, the axial dimension oi said inner conductor being substantially perpendicular to the longitudinal dimension of said first and second chambers and being disposedintermediate thejend Walls thereof, pairs of coaxial connectors for individual connection to said plurality of transmission lines" and having outer conductors conductivelyl'connected"to' said chamber walls, the inner conductorsof each pair of connectors extending into respective ones of said chambers on. opposite sides of the inner conductor o'f "the first connector, pairs of movable conductive fswitch arms having a substantially uniform cross-section defined by 0pposed pairs of parallel surfaces, one 'pair of each or said arms extending substantially "longitudinal wise "inia respective chamber for movement'from'one'to another or two positions wherein said first connector is alternately connected to and disconnected from respective onesof said plurality of connectors,-each arm having oneje n d conductively connected to and supported 'from a respective one of theinner conducotrsiof said pluralityand having a free end adapted for conductive connection with'the inner conductor of saidfirst connectorfjand means for operatingsaid switch arms wherein movement ofa'narm to 'a first of its positions causes he free end of said arr'nto contact condu'ctively'with'the chamber wall juxtaposed'the first inner conductor,'an'd movement of an arm to the second of its positions causes'itsfree'end to make contactlwith said first inner conductor wherein such arm and the coextending chamberfwall'surrounding same serve as a section'of coaxial line couplingsaidjfirst connector with the correlated connector of said'plurality.

References Cited in the file of this patent H UNITED STATES PATENTS Dorne Dec.-9,"l94 7 Ellis et al. July.17,'*l951

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