US2233476A

US2233476A - Electrode for gaseous tubes

Info

Publication number: US2233476A
Application number: US291682A
Authority: US
Inventors: Fletcher Milton
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-08-24
Filing date: 1939-08-24
Publication date: 1941-03-04
Anticipated expiration: 1958-03-04

Description

March 1941- M. FLETCHER I 2,233,476 I ELECTRODE FOR GASEOUS TUBES Filed Aug. 24, 1939 INVENTOR Milton Fletcher ATTORNEY Patented Mar. 4, 1941 UNITED STATES PATENT OFFICE ELECTRODE FOR GASEOUS TUBES Milton Fletcher, New York, N. Y.

Application August 24, 1939, Serial No. $1,682

' Claims. (cl. 176-126) This invention relates to new and useful improvements in an electrode for gaseous tubes.

Heretofore it has been customary to construct the electrodes in vacuum tubes of solid or hol- '5 low cylindrical forms in order to provide sufliand so reducing their life. This sputtering is known to occur during the manufacture of the vacuum tube as well as during its use, especially when an excess local potential gradient develops,

. on or in the vicinity of the electrodes.

Numerous attempts have been made to so construct the electrodes, or the material of the tube surrounding it. to eliminate or reduce this sputterin g. Such attempts have met with little success.

This invention particularly proposes a novel construction of the electrode so as to reduce, and very often completely eliminate the sputtering complained of. Particularly the invention proposes the use of wire coiled into hollow cylin- 3'0 drlcal or hollow conical form, or other forms, to

form the main body of the electrode. It is proposed that the turns of these coils be closely wound. when the electrode is thus made it will be found that the ends are round due to the cur- 35 vature of the wire, and moreover the side walls of the electrodes are formed with small rounded ridges, or areas, which comprise the round shape of the wire forming the coil. It has been found that the electrode so constructed will have a rela-' tively lower flux density and a lower distribution of the dielectric flux which avoids disruption of' the metal forming the electrode and so avoids sputtering.

Still further the invention proposes a novel means for supporting the new electrode in a vacuum tube.

' Still further the invention proposes'the construction of an electrode as mentioned which is 50 simple and durable and which may be manufactured and sold at a reasonable cost.

' For further comprehension of the invention, and of the objects arid advantages thereof, reference will be had to the following description 55 and'acccmpanying drawing, and to the appended claims in which the various novel features of the invention are more particularl set forth. Fig. l isa fragmentary elevational view of a portion of a vacuum tube with an electrode constructed in accordance with this invention. 5

of an electrode constructed in accordance with a still further. modification of this invention.

Fig. 7 is a horizontal sectional view taken on the line I -I of Fig. 6. 20

The electrode for gaseous tubes in accordance with this invention includes a wire coil ill for engagement within a gaseous tube II, and provided with a terminal wire it attached to its rear end, and extending from the tube II. The

coil III is formed from a length of rounded wire which is closely wound. The bottom portion ill of the coil, and at its rear end, has its coils tapering forming a tapered rear end portion III". This rear end portion terminates in the wire end HP which iscoaxial with the coil.

The terminal I2 comprises a length of wire which is bent at its center l2 and which is mounted on one of the turns of the rear end III of the coil. This wire I2 is formed with several turns I2 constructed by twisting an area thereof, immediately adjacent the bent end Il The terminal may be engaged upon the turns of the rear end HI by engaging the bent end I! over the free end |0 and then moving the bent end 40 i2- around and around to move it along the turns of the wire forming the rear end Ill".

The electrode may be engaged into the end H of the tube II and may be supported by the terminal wire l2, and then the tube Il may be '45 sealed in the regular way. A sheet of insulating material 14 of such dielectric strength and high permittivity is rolled into a hollow cylindrical form and is disposed within the end .of the tube H, and encases the electrode Ill. This insulation material I 4 assists in lowering the maximum potential gradient occurring between the electrode and the wall of the tube and so assist in preventing the disruption and sputtering previously explained.

20 and an inner coil 2!.

In Figs. 4 and 5 a modified form of the invention has been disclosed which distinguishes from the prior form in the way in which the terminal I2 is mounted in'position. According to this form of the invention the terminal I2 has a loop end l2 which is engaged transversely across a solid conical member l5 mounted within the conical rear end Ill of the electrode. This conical member l5 has longitudinally extending grooves l6 along the diametrically opposite sides. The side portions of the loop l2" extended through these grooves. The side portions of the loop l2 continue downwards and out from the open rear end of the electrode. and extend past the sides of the end F of the wire which forms the electrode. The terminal l2 has a twisted area l2 immediately adjacent the end In for assisting in holding the terminal in position.

In Figs. 6 and 7 another form of the invention has been disclosed which distinguishes from the prior form in the fact that the electrode is made from two coils of wire, one set into the other. Specifically the electrode comprises an outer coil The outer coil 20 has its rear end 20 formed into frusto-conical form. The inner coil has its rear end ill in similar form. A wire terminal 22 has a central loop portion 22 engaging over one of the turns of the inner coil 2|. downwards out throughthe opening of the coil 20, and engages against the tail end 2|! formed by bending the free rear end of the coil 20 centrally.

The terminal wire 22 also has a twisted portion 22' arranged immediately. adjacent the end 20 so that the parts are somewhat rigidly connected. The cells 20' and 2| contact each other. The flux density at the front end of the coil will be distributed to the ends of both of the coils, and will distribute and reduce the dielectric flux and thus avoid disruption of the metal forming the coils.

It is proposed that the electrode be made from stainless steel wire such as nichrome wire which is especially good for high intensity and fluorescent tubing, but may also be made of nickel. chromium, or Monel metal, or other wire found suitable for this purpose.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise constructions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims. a

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. An electrode for gaseous tubes. comprising a 2 wire coil for engagement with a gaseous tube having its rear turns progressively reduced in diameter to present a frusto-conical shape, said wire coil having the rear end of the wire from.

lar end of said coil wire disposed from said coil.

2. An electrode for gaseous tubes, comprising This loop portion 22 extends a .wire coil for engagement with a gaseous tube having its rear turns progressively reduced in diameter to present a frusto-conical shape, said wire coil having the rear end of the wire from which it was formed extended from the rear end of said coil and bent at right angles to the axis of said coil, and a U-shaped terminal wire having the junction of its arms disposed within the frusto-conical portion of said coil, said terminal wire having its arms extended from the rear end of said coiland along opposite sides of the right angular end of said coil wire and twisted about each other adjacent the face of said right angular end of said coil wire disposed from said coil, and a conical shaped member set into the frustoconical shaped rear end of said coil,- said terminal wire having the junction of its arms engaged oversaid conical shaped member.

3. An electrode for gaseous tubes, comprising a wire coil for engagement with a gaseous tube having its rear turns progressively reduced in diameter to present a 'frusto-conical shape, said wire coil having the rear end of the wire from which it was formed extended from the rear end of said coil and bent at right angles to the axis of said coil,'and a U-shaped terminal wire having the junction of its arms disposed within the frusto-conical portion of said coil, said terminal wire having its arms extended from the rear end of said coil and along opposite sidesof the'right angular end of said coil wire and twisted about each other adjacent the face of said right angular end of said coil wire disposed from said coil; and a conical shaped member set into the frusto conical shaped rear end of said coil, said terminal wire having the junction of its arms engaged over said conical shaped member, said conical shaped member being formed with longitudinal grooves on diametrically opposite sides thereof forming passages between the adjacent faces of said conical member and said coil through diameter to present a frusto-conical shape, said' wire coil having the rear end of the wire from which it was formed extended from the rear end of said, coil and bent at right angles to the axis of said coil, and a U-shaped terminal wire having the junction of its arms disposed within the frusto-conical portion of said coil, said terminal wire having its arms extended from the rear end of said coil and along opposite sides of the right angular end of said coil wire and twisted about each other adjacent the face of said right angular end of said coil wire disposed from saidfcoil, said coil, comprising an outer coil and a complementary inner coil disposed within said outer coil, said right-angular end portion beingextended from the rearmost turnof said outer coil.

5. An electrode for gaseous tubes, comprising a wire coil for engagement with a gaseous tube having its rear turns progressively reduced in diameter to present a frusto-conical shape,- sald wire coil having the rear end of the wire from.

which it was formed extended from the rear end of said coil and bent at right angles to the axis of said coil, and a U-shaped terminal wire having the junction of. its arms disposed withinthe frusto-conical portion of said coil, said terminal wire having its arms extended from the rear end of said coil and along opposite sides of the right angular end of said coil wire and twisted about each other adjacent the face of said right angular end of said coil wire disposed from said coil, said coil, comprising an outer coil and a complementary inner 'coll disposed within said outer coil, said right-angular end rtion being extended from the reannost turn of said outer coil, said terminal wire having the junction of its arms looped over a. turn of the frustoconical portion of said inner coil to'cooperate with the turned portion of the arms of said ter minal wire in locking said coils together.

MILTON FLETCHER.