US2640115A - Electrical switch - Google Patents

Description

y 26, 1953 c. w. CONCELMAN 2, ,1

ELECTRICAL swncu Filed May 1, 1951 INVENTOR. CARL W. CONCELMAN M I M ATTORNEY Patented May 26, 1953 ELECTRICAL swlron Carl W. Conoelman, Brookfield, Conn, assignor to Hazeltine Research, Inc., Chicago, 111., a corporation of Illinois Application May 1, 1951, Serial No. 224,045

Claims.

General The present invention relates to electrical Switches for selectively connecting a first highfrequency coaxial transmission line to either of a pair of such lines.

Various types of electrical switches have heretofore been proposed for selectively interconnecting coaxial transmission lines. One prior switch selectively connects a first transmission line to any of a plurality of other transmission lines by selectively connecting and disconnecting both the inner and outer conductors of each of the lastmentioned transmission lines and the corresponding conductors of the first transmission line. Other prior switches selectively connect and disconnect only the inner conductors of the transmission lines. These prior switches generally are somewhat more complex in structure and therefore more costly than is desirable for some applications.

It is an object of thepresent invention therefore, to provide a new and improved electrical switch which avoids one or more of the abovementioned disadvantages of prior such switches.

It is another object of the invention to provide a simple and inexpensive electrical switch for selectively connecting a first high-frequency wavesig'ua] coaxial transmission line to either of a pair of such lines.

It is a further object of the invention to provide a new and simple electrical switch adapted for use in the high-frequency range and which may be readily constructed by screw machine operations. v

In accordance with a particular form of the invention, an electrical switch for selectively connecting a first high-frequency wave-signal coaxial transmission line to. either of a pair of such lines comprises a support having a chamber defined by conductive walls. The switch includes a pair of coaxial connectors for individual connection to the aforesaid pair of transmission lines and having outer conductors conductively connected to the chamber walls and extending therefrom in substantially the same plane and having inner conductors extending into the aforesaid chamber. The switch also include a third coaxial connector for connection to the aforesaid first transmission line and having an outer conductor conductively connected to the chamber walls and extending therefrom substantially normal to the aforesaid plane and having an inner conductor extending into the above-mentioned chamber. The chamber walls having portions which are effectively tangential to the outer conductors of the aforesaid pair of connectors and have a dimension normal to the above-mentioned plane which is approximately equal to the diameter of the outer conductors of the aforesaid pair of connectors. The switch also includes a movable selector mounted on the support for conductively connecting the inner conductor of the third connector to the inner conductor of either of the above-mentioned pair of connectors.

For a better understanding of the present invention, together with other and further objects. thereof, reference is had to the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

In the accompanying drawing, Fig. 1 is an exploded elevational view, partly in section, of an electrical switch constructed in accordance with a particular form of the invention; and Fig. 2 is an end elevational view of a portion of the switch as seen along the line 2-2 of Fig. 1.

Description of electrical switch Referring now more particularly to Fig. 1, ther is represented an exploded view of a switch It including a solenoid motor I I for actuating the switch. The switch It includes a support comprising a cup-shaped housing I2 having a stepped axial bore I5, a notched member I3 (shown in Fig. 2), and a cylindrical cover I4 for the housing I2, all constructed of a suitable material such as brass which is then silver-plated. The housing I2 includes a mounting flange I6 at the mouth of the bore I5.

The notched member I3 preferably is essentially cylindrical with a wedge-shaped notch therein as illustrated in Fig. 2. The member I3 is adapted to be positioned in the bore I5 of the housing I2 by any suitable means such as by silver oldering. When the cover I4 is attached to the housing I2 in a manner to be described subsequently, the housing It, the notched member I3 and the cover I4 form a wedge-shaped chamber I I defined by conductive walls 20 and 2| of the housing, by one wall of the cover It and by conductive portions I8, I9 and 50 of the notched member I 3, hereinafter referred to for convenience as walls I8, I9 and 50. Wall I8 is disposed at an acute angle with reference to the wall I9 and arcuate wall 50 connects corresponding ends of the walls I8 and I9.

A pair of coaxial connectors 22 and 23, for individual connection to a pair of transmission lines (not shown), have the respective outer conductors 24 and 25 thereof conductively connected to the housing I2 and, hence to the chamber wall 2|, and extend therefrom in substantially the same plane; that is, the longitudinal axes of these connectors are in substantially the same plane. As may be seen more clearly in Fig. 2, the connectors 22 and 23 have inner conductors 26 and 2?, respectively, which preferably extend into the enlarged portion of the chamber II. More particularly, the connectors 22 and 23 extend radially from the housing I2 at substantially the aforesaid acute angle relative to each other. The connectors 22 and 23 may be of any suitable type and may, for example, comprise connectors of the type described and claimed in Patent No. 2,540,012, entitled Electrical Connector, granted January 30, 1951 to O. M. Salati.

The switch also includes a third coaxial connector 28, which is similar to the connectors 22 and 23 as may more clearly be seen in Fig. 1, for connection to a first transmission line. The connector 28 has an outer conductor 29 conductively connected to the housing I2, and hence to the chamber wall 29, and extends therefrom substantially normal to the aforesaid plane. More particularly, the connector 28 extends axially from the support l2 and includes an inner conductor 30 which extends into the reduced portion of the chamber IT as may be seen in Fig. 2. It will be understood that the inner conductors of the three connectors 22, 23 and 2B are spaced from the outer conductors thereof by suitable bodies of dielectric material, such as insulators 3| and 32 represented in Fig. 1.

As represented in Fig. 2, the walls of the chamber ll, specifically the walls I8 and I9. are effectively tangential to the outer conductors 24 and 25 of the pair of connectors 22 and 23, respectively. By effectively tangential, it is meant that portions of the chamber walls lie in planes which are substantially tangent to the outer conductors of the above-mentioned pair of connectors. More particularly, the chamber walls l8, I9 and 59 are effectively tangential to the outer conductors of the three connectors 22, 23 and 28, respectively. As may clearly be seen by referring to the notched member I3 in Fig. 1, the chamber walls also have an axial dimension a normal to the plane of the pair of connectors 22 and 23 and which is approximately equal to the diameter of the outer conductors 24 and 25 of the connectors 22 and 23.

The cylindrical cover I4 represented in Fig. 1 preferably has an axial bore 33 therein at one end thereof and is of reduced diameter at the other end thereof so that the cover I4 may be nested in the axial bore I5 of the housing |2 to enclose the chamber 1. A conductive wall 34 of the cover I4 then forms the remaining wall of the chamber IT.

The switch I also includes a movable selector mounted on the cover I4 for conductively connecting the inner conductor 30 of the third connector 28 to the inner conductor of either of the pair of connectors 22 and 23. The movable selector comprises a member 35 rotatably mounted in an aperture in the cover 14. One end of the rotatable member 35 is hollow and has a kerf 52 therein for a purpose to be explained subsequently. A body of dielectric material 36, such as polystyrene, is attached to the other end of the member 35 as by a screw 31. A metallic washer 38 is positioned intermediate the dielectric material 36 and the conductive wall 34. A resilient leaf spring 39 of a suitable conductive material such as beryllium copper is attached to the body of dielectric material 36 by a rivet 40.

Any suitable means, such as the solenoid Il, may be utilized to rotate the member 35 relative to the cover I4. To this end, the solenoid l| includes a rotatable shaft 4| having a pin 42 extending diametrically therefrom for engagement with the kerf 52 of the member 35. A flat coil spring 43 is attached to the shaft 4| and mounted on the solenoid by a clamp 44 for maintaining the shaft 4| in one position when the solenoid II is in a de-energized condition. The solenoid may be energized by the application of a suitable energizing potential to a pair of input terminals 45, 45 thereof. The shaft 4| extends through the solenoid II and may be utilized manually to rotate the member 35.

The elements of the switch I0 and the solenoid I| may be locked together by any suitable means such as three screws 46 (only one of which may be seen in Fig. 1 of the drawing) which may be passed through corresponding bores 41, 48 and 49 (see also Fig. 2) in the mounting flange l6 of the housing I2, the cover, I4 and the solenoid II, respectively.

From the foregoing description it will be seen that the metallic parts of the switch I0, except for the leaf spring 39, may be formed from cylindrical members which lend themselves to fabrication by inexpensive screwmachine operations. The various bores and apertures of the housing l2 and the cover H are formed quickly and conveniently by screw machine operations. The outer conductors 24, 25 and 29 of the connectors 22, 23 and 28, respectively, 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 by insulators. The members l3 and 35 may be made by a simple screw machine and milling operation and the leaf spring 39 may be fabricated by a simple stamping operation. Thus the manufacture of the electrical switch It) lends itself to mass production techniques and the cost thereof is relatively small.

Operation of electrical switch.

When the switch I0 and solenoid II are assembled and the solenoid is in a de-energized condition, the leaf spring 39 is maintained in the chamber IT in contact with the inner conductor 30 of the connector 28 and the inner conductor 2! of the connector 23 as represented in dotclash construction in Fig. 2. When the solenoid H is in an energized condition, the shaft 4| thereof rotates and causes the leaf spring 39 to pivot about the inner conductor 30 of the con nector 28 and thus connect the inner conductor 3|] to the inner conductor 26 of the connector 22. Upon de-energizing the solenoid, the spring 43 causes the shaft 4| again to rotate and to return the leaf spring 39 to the position indicated in Fig. 2.

It is well known that the characteristic impedance of a high-frequency wave-signal coaxial transmission line is related to 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 l1 and the leaf spring 39. Accordingly, the enlarged portion of the wedge-shaped chamber preferably is maintained as small as practicable in order to minimize any impedance discontinuity between the transmission line attached to the connector 2'2'01' 23 and the transmission line attached tothe connector 28', the connectors 22, 23- and- 28 being effective to provide an approximate impedance match between the transmission lines attached thereto and the transmission line formed by the chamber l1 and the leaf spring 33. Similarly, for this reason, the dimension as of the chamber walls l8 and i9 is so proportioned as to be approximately equal to the diameter of the outer conductors 24 and 25 of the connectors 22 and 23, respectively. The thickness and width of the leaf spring 39 may then be selected approximately to provide a desired capacitance between the leaf spring and the chamber walls and thus approximately to provide an impedance match between the transmission line connected to the connector 22 or 23 and the transmission line connected to the connector 28.

While applicant does not. wish to be limited to any particular dimensions, the followingare dimensions employed in a switch constructed in accordance with the invention for use at signal frequencies of about 1000 megacycles:

Angle between walls l8 and i9 degrees 45 Dimension 11 inch 2 Radius of wall 50 do Extension of inner conductor into chamher I! inch Extension of inner conductors 26 and 21 into chamber 11 inch it; Length of leaf spring 39 do Width of leaf spring 39 do 3% Thickness of leaf spring 39 do .005

From the foregoing description it will be apparent that a switch constructed in accordance with. the invention has the advantage of being simple in construction and inexpensive to manufacture.

While there has been described what is at present considered to be the preferred embodiment of this invention, it will be 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 in the appended claims 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 switch for selectively con.- necting a first high-frequency Wave-signal coaxial transmission line to either of a pair of such lines comprising: a support having a charm ber defined by conductive walls; a pair of coaxial connectors for individual connection to said pair of transmission lines and having outer conductors conductively connected to said chamber Walls and extending therefrom in substantially the same plane and having inner conductors extending into said chamber; a third coaxial connector for connection to said first transmission line and having an outer conductor conductively connected to said chamber Walls and extending therefrom substantially normal to said plane and having an inner conductor extending into said chamber; said chamber Walls having portions which are effectively tangential to said outer conductors of said pair of connectors and having a dimension normal to said plane which is approximately equal to the diameter of said outer conductors of said pair of connectors; and a movable selector mounted on said support for concluotively connecting said inner conductor of said third connector to the inner conductor of either of said pair'of con nectors- 2. An electrical switch for selectively connecting a first high fre'quency wave-signal coaxial transmission line to either of a pair of such lines comprising: a cylindrical support having a chamber defined by conductive walls; a pair of coaxial connectors for individual connection to said pair of transmission lines and having outer conductors conductively connected to said chamber walls and extending radially from said support in substantially the same plane and having inner conductors extending into said chamber; a third coaxial connector for connection to said first transmission line and having an outer conductor conductively connected to said chamber walls and extending axially from said support and having an inner conductor extending into said chamber; said chamber Walls having portions which are effectively tangential to said outer conductors of said pair of connectors and having an axial dimension which is approximately equal to the diameter of said outer conductors of said pairof connectors; and a movable selector mounted on said support for conductively connecting said inner conductor of said third connector to the inner conductor of either of said pair of connectors.

3. An electrical switch for selectively connecting a first high-frequency wave-signal coaxial transmission line to either of a pair of such lines comprising: a cylindrical support having a Wedge-shaped chamber defined by conductive walls; a pair of coaxial connectors for individual connection to said pair of transmission lines and having outer conductors conductively connected to said chamber walls and extending radially from said support in substantially the same plane and having inner conductors extending into the enlarged portion of said chamber; a third coaxial connector for connec tion to said first transmission line and having an outer conductor conductively connected to said chamber walls and extending axially from said support and having an inner conductor extending into the reduced portion of said chamber; said chamber walls having portions which are effectively tangential to said outer conductors of said three connectors and having an axial dimension which is approximately equal to the diameter of said outer conductors of said pair of connectors; and a movable selector mounted on said support for conductively connecting said inner conductor of said third connector to the inner conductor of either of said pair of connectors.

4. An electrical switch for selectively connecting a first high-frequency wave signal coaxial transmission line to either of a pair of such lines comprising: a support having a chamber defined by conductive walls, two of which are disposed at an acute angle; a pair of coaxial connectors for individual connection to said pair of transmission lines and having outer conductors con" ductively connected to said chamber walls and extending therefrom in substantially the same plane and at substantially said acute angle relative to each other and having inner conductors extending into said chamber; a third coaxial connector for connection to said first transmission line and having an outer conductor conductively connected to said chamber walls and extending therefrom substantially normal to said plane and having an inner conductor extending into said chamber; said two of said chamber walls being efiectively tangential to said outer conductors of said pair of connectors and having a dimension normal to said plane which is approximately equal to the diameter of said outer conductors of said pair of connectors; and a movable selector mounted on said support for conductively connecting said inner conductor of said third connector to the inner conductor of either of said pair of connectors.

5. An electrical switch for selectively connecting a first high-frequency wave-signal coaxial transmission line to either of a' pair of such lines comprising: a support having a chamber defined by conductive Walls; a pair of coaxial connectors for individual connection to said pair of transmission lines and having outer conductors conductively connected to said chamber walls and extending therefrom in substantially the same plane and having inner conductors extending into said chamber; a third coaxial connector for connection to said first transmission line and having an outer conductor conductively connected to said chamber walls and extending therefrom substantially normal to said plane and having an inner conductor extending into said chamber; said chamber walls having portions which are effectively tangential to said outer conductors of said pair of connectors and having a dimension normal to said plane which is approximately equal to the diameter of said outer conductors of said pair of connectors; and a movable selector including a conductive leaf spring positioned in said chamber and rotatably mounted on said support for conductively connecting said inner conductor of said third connector to the inner conductor of either of said pair of connectors.

CARL W. CONCELMAN.

References Cited in the file 01 this patent UNITED STATES PATENTS Number Name Date 2,408,779 Jenks et al. Oct. 8, 1946 2,413,298 De Tar Dec. 31, 1946 2,426,186 Dow Aug. 26, 1947 2,565,643 Baddour Aug. 28, 1951

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