US1536855A - Electron-discharge device - Google Patents

Description

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W. G. HOUSKEEPER ELEGTRON DISCHARGE DEVICE Filed July 20, 1920 May 5, 1925.

Patented May 5, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM Gi HOUSKEEPER, F NEW YORKN. Y., ASSIGNOR TO AWESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A. CORPORATION OF NEW YORK.

ELEOTRON-DISCHARGE DEVICE.

Application filed July 2o, 1920. serial No. 397,764.

l" 'lhis invention relates to electron discharge devices, such as the audion, and pertains more especially to the electrode supporting structure and the arrangement of the lead wires for the electrodes.

-" fin object of this invention is to provide a rugged and compact electrode unit which is capable of being subjected to high voltages without injury. Another object is to provide a simple and efficient means of supporting such an electrode unit. A further object is to prevent leakage currents between the lead-in wires for the various elec trodes of a vacuum tube. Still other objects will be apparent from the detailed descript-ion of the drawings.

For convenience this invention will be illustrated and described in connection with a tube of the three-electrode type comprising an anode, .a cathode and a control or grid electrode enclosed in a gas tight, preferably evacuated vessel.

The electrode unit hereinafter described in detail as constituting one form of this invention, comprises a flattened cylindrical anode supporting at either end a block of insulating material. The cathode and grid electrodes are located within the anode and are supported by suitable means fastened to the blocks of insulating material. The electrode unit comprising the three :above mentioned electrodes is supported in the tube by having the anode terminate in a metallic collar which surrounds an inwardly projecting neck of the containing vessel and which is preferably frictionally held thereto.

Such a structure is very rugged and is adapt-ed to be employed with high anodecathode voltages.

In employing such a tube in high voltage afi circuits, special precautions are frequently necessary to prevent discharges or corona effects between the various lead-1n wires for the electrodes or between one of the wires and the above mentioned supporting collar and also to prevent appreciable leakage currents through the glass located between the lead-in wires due to high frequency potential differences therebetween. These deleterious effects may be prevented by surrounding one or more of the lead-in wires by evacuated glass tubes in a manner hereinafter described in detail.

This invention will be better understood by reference to the following detailed description taken in connection with the accompanying drawings in which Fig. 1 represents a. vacuum tube of the three-electrode type embodying this invention; Fig. 2 represents a. modification of the sealing-in arrangement for the lead-in wires of the tube and Fig. 3 illustrates how the tube of this invention may be employed in an electric circuit for amplifying or repeating electric currents.

The electron discharge device illustrated in F ig. 1 comprises an evacuated container 5 of glass which has an inwardly projecting neck 6 also of glass. The flattened cylindrical anode of the electrode unit of the device is supported by two T-shaped members, 8 and 9, which are fastened to a metallic collar 10 surrounding neck 6. The collar 1() is maintained in position on neck 6, preferably by friction only. Collar 1() is preferably made crimped in a plurality of places and is fashioned so as to originally have an effective diameter slightly less than the diameter of the neck G. The collar 10 may then be forced on neck 6 so that it is tightly held thereto by friction.

Fastened on opposite sides of anode 7 are metallic posts 12 and 13 for supporting at either end of the anode, blocks of insulating material 14 and 15. The blocks 14 and 15 are preferably made of lavite, since such a material can be readily machined and freed of absorbed gases. The use of lavite, however, in a vacuum tube is not a part of this invention, but is described and claimed in a copending application of William A. Knoop, filed April 18, 1919, Serial No. 290,968.

lVithin the anode 's' is located a double fill-shaped filament 17 supported at one end by wires 18 and by wires 19 at the other end. Wires 19 are preferably rigidly set in the lavite block 15, while wires 18 pass up throu h apertures in block 14 and are resilient y supported. by springs 20: This manner of resiliently supporting a filament is not a. part of this invention, but is described and claimed in a copending application of Paul A. Watrous, led November 25, 1919, Serial No. 340,455. .\J

The control or grid electrode for the device comprises a helical w-ire 25 wh1eh 1s welded at a plurality of points to a plurality of wires 26, 27, 28 and 29. Upright wires 26 and 28 are ri idly connected at their lower ends to insu ating block 15; at their upper ends, wires 26 and 28 pass loosely through apertures 1n block 14 so as to allow the expansion of the grid electrode due to heat. Upright wires 27 and 29 are preferably not fastened to either of the blocks 14 or 15 since it is generally found suicient to fasten only two of the vertical grid wires to the insulating blocks.

External connections for the anode, cathode andA grid are provided by the lead-in wires 30, 31, 32 and 33, lead-in wire 30 being connected to the grid, wire 3l being connected to the two ends and wire 32 to the midpoint of the double M-shaped filament and wire 33 being connected to the anode. It is to be noted that wire 30 is not sealed in the glass at the point 35 of the neck as is the usual practice, but instead is sealed in the glass at the lower end of an evacuated tube k36, the other end of which is sealed to the point 35 of the neck of the tube. Leadin wire 30 is therefore surrounded by a vacuum from the point 35 to point 37. The lead-in wire 33 for the anode is similarly sealed in at the lower end 40 of an evacuated' tube 41, the upper end of which is sealed to the point 42 of the neck 6. Such an arrangement increases enormously the distance along the glass between the points where the lead-in wires 30 and 33 are sealed in the glass with respect to the sealing-in point for the cathode. Leakage currents between the various lead-in wires by means of these evacuated tubes is therefore reduced to a negligiloleV value on account of the long leakage path between the sealing points of the leadin wires. The provision of the evacuated tubes 36 and 41 also aids in preventing arcing or other discharges between the portion of the lead-in wires enclosed or surrounded bythe neck 6. In order to aid in insulating the filament lead-in wires 31 and 32 from the other lead-in wires of the tube it is frequently found convenient to surround the Wires 31 and 32 by glass tubes 45 and 46 which, however, need not necessarily be evacuated. Similarly, glass tubes. 47 and 48 may be placed on lead-in Wires 30 and 33 at their lower ends for aiding in the insulation of these two wires from the filament lead-in wires.

Another way in which -leakage currents between the sealing-in points of the lead-in wires may be reduced to negligible value is shown in Fig. 2. In this modification the tw(l filament lead-in wires 31 and 32 are surrounded by an evacuated tube 50 to which the lead-in wires are sealed only at the lower .end 51. lSimilarly the grid lead-in wire 30 is enclosed in an evacuated tube 52 as in Fig. 1. The lead-in wire 33 for the anode in this modification, need not be enclosed in an evacuated tube, since ample protectionfrom leakage currents over the glass andA -discharges between the lead-in wires is secured by tubes 50 and 52.

One way in which the tube illustrated in Fig. 1 may be employed for repeating electric currents is shown in Fig. 3 inwhich the tube 5 is shown as having its input terminals connected by a transformer 55 to an incoming line 56, whiley its outputvterminals are connected by a transformer 57 to an outgoing line 58. Cathode l7-is heated by a battery 59 while space current for the tube is provided by a source of Volt-age 60. The source of Voltage 60 for the type of tube disclosed in Fig. 1 may safely be as high as 2000 volts or more. With such an arrangement tube 5 may be employed for repeating to line 58 amplified currents received by tube 5 from line 56.

It is to be understood that the electrode structure above describedrepresents only one form in which applicants invention may be used and that the above described form may be variously modified without` departing in anywise from the spirit of this invention as defined in the appended claims.

What is claimed is:

1. An electron discharge device comprising a gas tight vessel having a reentrant in` tegral stem, a metallic collar held to said stem solely by friction, and an electrode supported by said collar.

2. An electron discharge device comprising a gas tight vessel having an inwardly projecting neck, a crimped metallic collar on said neck, and an electrode supported by said collar.

3. An electron discharge device comprising a gas tight vessel having an inwardly projecting neck, a crimped metallic collar surrounding said neck, an electrode unit in said vessel and a plurality of T-shaped members fastened to said collar for supporting said unit.

4. An electron discharge device comprising a cathode, a control elect-rode, an an'ode surrounding said cathode and control electrode, pair of supports carried by said anode out of contact with the major por- Vtion of said anode, said pair of supports being located at opposite ends of said anode and means for supporting said cathode and control electrode from said pair of supports.

5. An electron discharge device comprising a gas tight vessel having an inwardly projecting neck, an anode supported by said neck, a pair of supports carried by said anode out of contact with the major portion of said anode, said pair of supports being located at opposite ends of said anode, a cathode, a control electrode and supporting means for said cathode carried by each of said pair of supports.

6. An electron discharge device comprising a gas tight vessel having an inwardly projecting neck, an anode supported by said neck, a pair of supports carried by said anode but out of contact with the major ortion of said anode, said pair of supports iieing located at opposite ends of said anode, a cathode, a control electrode and supporting means for said control electrode engaging each of said pair of supports.

7. An electron discharge device comprising a containing vessel having an inwardly projecting neck, an anode frictionally supported by said neck, cathode and control electrodes surrounded by said anode, a block of insulating material carried by said anode at either end thereof and supporting means for said control electrode engaging each of said blocks.

8. An electron discharge device comprising a containing vessel having an inwardly projecting neck, an anode supported by a crimped collar surrounding said neck, blocks of insulating material carried by said anode at opposite ends thereof, and cathode and control electrodes supported by said blocks.

^ 9. An electrode assembly comprising an anode, cathode and control electrodes surrounded by said anode, a block of insulating material carried by said anode at either end thereof and out of contact with the major portion of said anode and means for supporting said control electrode and said cathode between said blocks.

10. An electrode assembly comprising an electrode, a block of insulating material supported by said electrode at either end thereof and out of contact with the major portion of said electrode, a second electrode surrounded by said irst electrode and means for supporting said second electrode between said blocks.

l1. An electron discharge device comprising a gas tight vessel having a stem, a metallic collar surrounding said stem and held thereto by friction only, an electrode supported by said collar, a pair of insulating blocks supported by said electrode and a second electrode spaced between said blocks and supported thereby.

12. An electron discharge device comprising a gas tight vessel having a stem, an electrode supported by said stem, two blocks of insulatingmaterial supported by said electrode, said blocks having their greatest dimensions parallel to each other and parallel to a surface of said electrode and a second electrode mounted between said blocks and supported thereby.

13. An electron discharge device comprising a containing vessel having an inwardly projecting neck, a cathode, an anode surrounding said cathode and supported from said neck, a block of insulating material carried by either end of said anode, said blocks having their greatest dimensions arallel to each other and parallel to a surace of said anode, said cathode being' mounted between said blocks and supported thereby.

14. An electron discharge device comprising a stem, an anode supported by said stem, a block of insulating material at either end of said anode, said anode having projections passing through apertures in each of said blocks whereby said blocks are fastened to said anode, a cathode, a control electrode and supporting wires for said cathode and control electrode inserted in apertures in each of said blocks.

15. An electron discharge device comprisan evacuated vessel having a stem, an electrode supported by said stem, a tubular member carried by the stem and communicating with the interior of the vessel a leadin wire for said electrode passing through said stem and sealed in the outer end of said tubular member, said lead-in wire being out of electrical contact with said tubular member except at the sealing-in point.

16. An electron discharge device comprising an evacuated vessel having a stem, cathode, control and anode electrodes supported by said stem, lead-in wires for said electrodes passing through said stem, an evacuated tubular member within said stem and surroundingV a plurality of said lead-in wires.

17. An electron discharge device compris- Ving an evacuated vessel having an inwardly projecting neck, cathode, anode and control electrodes supported by said neck, lead-in wires for said electrodes passing through said neck and an evacuated tubular member of insulating material surrounding the cathode and control electrode lead-in wires.

18. An electron discharge device comprising an evacuated vessel havin a neck, the interior of said neck being su stantially at atmospheric pressure, electrodes in said vessel, lead-in wires within said neck for said electrodes and evacuated tubular members within said neck and surrounding a plurality of said lead-in wires.

19. An electron discharge device comprising an evacuated vessel havin an inwardly projecting neck, cathode, ano e and control electrodes supported by said neck, lead-in wires for said electrodes passing through said neck and evacuated tubular members of one of said electrodes sealed in said stem,

and a tubular member surroundin said lead-in wire for -preventing electrlc disvchar e effects lfrom said wire, said tubular mem er being free of electrical conductive material except'for said lead-in wire.-

21. An electron discharge device comprising an evacuated vessel having an inwardly projecting neck, an anode supported by a metallic collar attached to said neck, a cathode, a lead-in wire for said cathode sealed in said neck, and a tubular member surroundin the portion of said wire adjacent said coar for preventing corona e'ects between said wire and said collar when high voltages are applied to said anode and cathode, said tubular member being free of electrical conductive material other than said lead-in wire.

22. An electron discharge device comprising an evacuated vessel having a neck, a plurality of electrodes, 'lead-in Wires sealed 1n said neck for said electrodes,and a tubular member cooperating with 'said neck to provide a housing for one of said lead-in wires for preventing discharge eiects from the housed lead-in wire, said tubular member being free of electrical conductive material other than said lead-in wire.

23. An electron discharge device comprising a containing vessel having a neck, a collar engaging said neck, and an electrode supported by said collar, said collar having corrugations extending in the direction of its axis for rendering said collar expansible.

24. An. electron discharge device comprising a containing vessel having a neck, a normally contracting readily. -eX ansible collar adapted to be expanded an slipped over said .neck and released to grip the same, and an electrode su ported b said collar.

In witness w ereof, I hereunto subscribe my name this 14th da of Jul A. D., 1920.

VWILLIAM HOU KEEPER.

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