US2914639A - Coaxial switch - Google Patents

Description

Nov' 24,

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R' R FREI-:LAND

2914639 COAXIAL SWITCH Filed Aug. 2O 1957 wmmmfm ATTORNEYS United States Patent'lQ COAXIAL SWITCH Roya-en R. Freeland, oklahoma city, olea.

Application August 20, 1957, Serial No. 679,177 l16 claims. (cl. zoo-iss) Thisinvention relatesr to a new and improved coaxial switchA designed to couple either of two signals to a tele-- vision receiver withoutinterference.

The invention comprises an outer tubular conductive casing withinwhich slides'a plastic barrel. In the middle of the barrel is mounted avleaf clip contact which runs completely through the barrel. The switching action is accomplished by sliding the plastic barrel't'o either end of the tube Vto make contact with the coaxial terminals mounted ateach end of the tube.

Prior to this invention coaxial switches-'were known but therswitches' according to the prior art'are more costly to produce, notas long lasting,Y and not as easy to operate as the switch according' to the present invention. For example, one such switch inthe prior art has an outer cylindrical member and inner conductive cylinder supported by two end members ofthe outer cylinderf' The switching action is accomplished by sliding amovable contact 'along the inner cylindrical conductive member.V Such an arrangement is subject to wear and the sliding contact often sticks on the inner cylindrical member making switching action diihcul-t. This wear also resultsl in poor contact, thus giving rise to interference with the signal `transmittedthrough the switch.

The objects and advantages of this invention can be better understood with reference to the following figures wherein:v f

Figure 1 shows an elevation view of the switch partly I Figure 3shows another cross sectionthrough Figure 1.

Figure`4 shows an exploded view illustrating the various parts of the switch in detail.

The switch consists of an outer cylindrical conductive casing 11 which has two slots 12 and 13 running longitudinally along the casing diametrically opposite to one another. Mounted on each end of the casing 11 are conductive caps 21 and 22 which fit over the casing 11. The caps are fastened to the casing by screws. Mounted respectively in the middle of the caps 21 and 22 are the coaxial terminals 14 and 15. These coaxial terminals have conductive surfaces, which are soldered to make contact with the caps 21 and 22, and conductive inner contact members 24 and 25 which are insulated from the outer surfaces. Fitting within the casing 11 is a plastic insulating cylindrical barrel 16, which has a shorter axial dimension than the casing 11. The barrel 16 has a smaller diameter than the inner wall of the casing so as to make a loose lit therewith. A leaf spring contact 27 is mounted in the casing between the plastic barrel and the inner wall of the casing opposite the lower slot 13. This spring serves to press the barrel 16 against the upper inner wall of the casing topositively locate the axial position of the barrel and provide friction to hold the barrel longitudinally in place in the barrel but with a small enough force that the barrel may be slid without diticulty. A handle 17 is mounted with a screw 2. lit in the'barrel 11 and this handle projects through the slot 12. vA third coaxialterminal 18"is mounted diametrically opposite/toV the handle 1-7 in the barrel 16. This terminalV1 makes a^n screw litE with the plastic barrel 1`6= and extends through the hole' in the center of the spring contact 27 and the slot 13. The terminal has' an outer conductive surface and a conductive inner contact member 26;.v which is insulated from the outer surface. The outer conductive surface of the coaxial terminal has a' flange 28 whichA presses against the spring contact' 27' andV firmly mounts4 it against `thebarrel 16. The contact spring 27 has the additional function of providing a conductive path between the casing 11 and theE conductive surface` of? the coaxial terminal 18. li/IountedS inthe middle ofthe-plastic barrel 16 is a leaf clip contactassembly 20 which runs throughout the length of th'e barrel and'has leaf clip contacts at each end'of the barrel. vThe member 26 makes contact with the leaf clip contact assembly in the exact center of the plastic barrel16. l

With-this construction, the barrel 16 can slide back and forthwithin the tube 11 and at one end of the barrel ybarrel' from one position 'tothe other andY this sliding is accomplished by means ofthe knob 17.'v y

InV the preferred embodiment the casing and the barrelhave been shown las cylindrical. However, they may .beYA oblong,l orany other configuration. It is necessary,

however, that the inner walls of the casing have-the shapeof the development of a movementl straight line maintained parallelzto a reference' line, so that thevbarrel will'-slidewithinl the-casing.' These and numerous other modifications can be made n the disclosed embodiment without departing from the spiritl and' scopey of. the invention which is to be limited only as defined in the appended claims;

l. A coaxial switch comprising a conductive tubular lcasing having slots 'defined therein running longitudinally on said cylindricalcasing, a cylindrical-barrel made' of insulating material making a sliding fit with theV inner walls of said casing having an axial dimension shorter than said casing, a handle mounted on said barrel and projecting through said one of said slots, a leaf clip contact member mounted in said barrel running axially throughout the length thereof, a conductor mounted in said insulating member making contact with said leaf clip contact member and projecting through the other of said slots, a first conductive cap covering one end of said casing, a conductor mounted in said cap 'but insulated therefrom and positioned so as to make contact with said leaf clip contact member when said insulating member is slid to said one end of said casing, a second conductive cap covering the other end of said casing,- a conductor mounted in said second cap but insulated therefrom and positioned so as to make contact with said leaf clip contact member when said insulating member is slid to the other end of said casing.

2. A coaxial switch comprising anouter conductive casing having an inner wall whoseV surface is in the shape of a development of the movement of a straight line which is constantly maintained parallel to a reference line, an insulating member making a sliding tit with said surface of the inner wall of said casing, a first conductor mounted on said insulating member, a second conductor mounted on said casing positioned to make contact with said rst conductor, and means to slide said insulating member within said casing to selectively make or break the conductive path between said conductors.

3. A coaxial switch as recited in claim 2 wherein said second conductor is `nsulatedlfrom said casing.

4. A coaxial switch as recited in claim 2 wherein said casing has a slot defined therein running in the same direction as said reference line and wherein Vsaid means to slide said insulating member comprises .a handle mounted on said insulating member and extending through said slot.

5. A coaxial switch as recited in claim 2 wherein said casing has a slot defined therein runningv in the .same

direction as said reference line and wherein there is ai4 third conductor directly connected to .said and extending through said slot.

6. A coaxial switch comprising an outer conductive casing having an inner wall of which the surface is in the shape of a development of the movementofa straight line which is constantly maintained parallelto a reference line, an insulating member making a sliding iit with said surface of the inner wall of said casing, a first conductor mounted on said insulating member, a second first conductor conductor mounted on said casing positioned to ContactV i said first conductor when said insulating member is `slid to a first position, a third conductor mounted on vsaid casing positioned to contact said first conductor when said insulating member is slid to a second position and means to slide said insulating member between said iirstand second positions.

7. -Acoaxial switch as'recited in claim 6 wherein said second and third conductors are insulated from said casing.

8. A coaxial switch as recited in claim 6 wherein saidi casing has a slot defined therein running in the same direction as said reference line and wherein said means to slide said insulating member comprises a handle mounted on said member and extending through said slot.

casing has a slot defined therein running in the same direction as said reference line and wherein there is provided a fourth conductor mounted on said insulating 9. A coaxial switch as recited in claim 6 wherein said member directly connected to said iirst conductor and i extending through said slot.

10. A coaxial switch as recited in claim' 6 wherein said first conductor runs from one end of said insulating member to the other in the same direction as said reference line and said second and third conductors are positioned to contact said conductor at opposite ends of said insulating member.

ll. A coaxial switch as recited in claim 10 wherein said first conductor comprises a leaf clip contact member.

12. A coaxial switch as recited in claim il wherein said casing has a slot defined therein running the same direction as said reference line and wherein there is provided a fourth conductor mounted in said insulating member directly connected to said leaf clip contact member, said fourth conductor extending through said slot.

13. A coaxial switch comprising an outer conductive casing, an insulating member making a sliding iit with the inner wall of said casing, a iirst contact member mounted in said insulating member, and a second contact member mounted on said casing, positioned to make contact with said first contact member, and means to slide said insulating member within said casing to selectively make or break the conductive path between said contacts.

14. A coaxial switch as recited in claim 13 wherein there is provided a leaf spring mounted on said insulating member to press against the inner walls of said casing.

l5. A coaxial switch comprising an outer conductive casing, an insulating member making a sliding t with the inner Wall of said casing, a contact member mounted in said insulating member, a coaxial terminal having an outer conductive surfacerand an inner contact member insulated from said surface, said terminal being mounted on said casing so that said outer surface makes contact with said casing, said terminal being positioned so that said inner contact member of said terminal makes contact with said rst mentioned contact member, and means to slide said insulating member within said casing to ,make or break the conductive pathv between said iirst mentioned contact member and said inner contact member of said coaxial terminal. f Y

16. Av coaxial switch as recited in claim 15 wherein a slot is dened in said casing and thereis provided a conductive leaf spring having a hole defined therein, -a second coaxial terminal having an outer conductive surface and an inner contact member insulated from said conductive surface, said coaxial terminal having a flange and being mounted on said insulating member, said tlange pinning said leaf spring to said insulating member between said member and the inner wall of said casing, said leaf spring pressing against the inner wall of said casing, said second coaxial terminal extending` through said slot.

References Cited in the tile of this patent UNITED STATES PATENTS 2,550,921 Greene V May 1,- 1951

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