US2542440A - Geiger tube - Google Patents

Description

Feb. 20, 1951 J. A. vlcToREl-:N Erm. 2,542,440

GEIGER TUBE 2 Sheets-Sheet l Filed April 14, 1947 NN ET WR Nm WW AR wR M .0. 0./ A w Feb. 20, 1951 ,filed April 14. 1947 WWI J. A. VICTOREEN Erm.

GEIGERTUBE 2 Sheets-Sheet 2 ,l la l, 11,11 1

/N VEN TORS JOHN A. V/CTUREE/V ROGER w BAR 0N Br d Patented Feb. 20, 1951 land, Ohio, assignors, by direct and mesne assignments; to The Victoreen Instrument Com- Dany Application April 14, 1947, Serial N0. .741,224A

3 Claims.

This invention relates to improvements in electronic tubes, and more particularly to gasA lled tubes, the gas of which is adaptedto be ionized upon being subjected to rays andV commonly known as a Jreiger-Muell`er tube.

Tubes of the class described have normally comprised an extremely thin waledfand' fragile glass envelope, the inner surfaceof which is coated with a conducting material, and having a center electrode. Usually the tube is lled with a gas such asargon" and' aV slightamount of alcohol vapor to provide a slight pressure.

The main disadvantages of these prior tubes was their fragility. Merely touching them with the fingers' wassunicientto cause their breakage. Obviously, atube so fragile could not withstand the shocks or rugged use which circumstances sometimes dictate vas'a necessary part of their operation.

By my present invention we have provided a be which is extremely rugged, can withstand relatively rough handlingr and is not liable to breakage even' under" circumstances where the usage is very rough;` This `enables thetube to be used in the field as well asthe laboratory,

thus increasing `greatly the-field oi use.

In the drawings:

Fig. l is a perspective View of a tube of my invention;

Fig, 2 is an explodedsecticnalview ofthe tube;

and

Fig. 3 is a vertical medial sectional View thereof.

Referring now to the drawings, throughout which like parts are designated by like reference characters, the tube includes a main chamber which is formed of a cylindrical copper body lil, the base of which is provided with an out turned flange II.

The upper end of the body is rolled over at .I

I2 and provided with an inwardly extending ange I3, the rolled over portion and the flange providing a seat Id on the upper surface.

The center electrode is supported by a coupling which includes a glass bushing I5 having welded thereto an alloy flange IE having an expan-sion characteristic that permits it to be Welded to the glass and which is adapted to seat on and be soldered on the seat i4. The bushing is provided with a tube i1 extending axially through and welded in the bushing. This tube may likewise be a similar alloy, one end extending into the chamber and the other end extending beyond the bushing adapted to` have soldered thereto at I8 a exble lead wire I9.

(Cl. Z50-275)' The inner end of the tube I1 has forced therein a terminal member 20,. the end .of which isof reduced diameter and split,`as indicated atv 2| to enable the same to have a close press t with the interior of the tube Il. The body of the terminal 2i] which extends beyond the tube Il is enlarged,.and it is providedwith aA bore, to the wall of which is spot welded a tungsten wire 22. The tungsten wire constitutes the center electrode. It is bent at its point'of emergence from the terminal so that it extends from the axis of the tube and axially of the chamber IB'. The extremity of the wire is provided with a small glass bead 23.

The tube` is provided with amica window at its A hanged end. Preferably a lead cushion washer 24 is disposed in engagement with the harige l I`, this washer being of slightly less diameter than the iiange. The mica window 25 seats on the washer 24 and then a second lead cushion washer 26, slightly larger than the mica window, is disposed in engagement with the other side of the mica, after which a lead cap 21 is placed over the assembly with its flange 28 extending beyond the edges of the ilange II, the washers 24 and 25, andthe window 25.

The window and its supporting washers thus assembled are cemented by a suitable insulating varnish, of which many types are suitable, and one of which is well known on the market' as glyptol varnish. The glyptol varnish as indicatedin Fig. 2 as 28"!wets the inner edge of the flange 28 and extends for a slight distance over the flange I I.

The varnish should preferably be one having high adhesion qualities and which does not dry and become brittle, but retains its flexibility over a long period of time.

After the varnish is applied, the flange Il and its assembled components is securely clamped. To this end a brass cap 30 is provided having a central opening 3I, and an internally threaded flange 32 adapted to extend upward over the edges of the assembly just described. The edge of the opening 3l is tapered toward its inner edge as indicated at 33.

The parts cooperating with the cap to clamp the assembly include a lead flange cushion washer 35, disposed adiacent the ilange I I, against which is disposed a brass washer 3e of slightly larger diameter and next a friction washer 3l of cold rolled steel. A threaded brass clamping ring 3S is provided, having external threads for engagement with the flange 32 of the cap. This washer is provided with holes 39 for engagement by a Spanner wrench when tightening the assembly.

3 After the parts are cemented as described, the assembly is then securely clamped together by assembling as stated and screwing the ring 38 securely into the flange.

There thenrremains the remaining steps of evacuation of the tube, which is readily effected through the hollow tube I1, after which it is lled with argon gas and ethyl acetate vapor in a ratio of 12 parts of argon to one part of ethyl acetate vapor to a pressure of approximately The end of the tube I1 is then sealed by a lead cap 6D which is soldered in place. This completes the tube and it is ready for use.

One of the advantages of the construction is that the body can be spun or drawn out so that the flange readily takes the cement. Being a copper spinning, it lends itself readily to being hydrogen red for the maximum cleanliness.

It will alsorbe appreciated that the cap 30 and its associated parts `may be secured in place by spinning the flange 32 over the washers 36 and 3?, omitting the ring 38 to hold the same Ain place and provide the desired mechanical clamp.

The construction also enables a very thin mica window to beused, thus reducing the absorption of .radiations through the window. The mica may be made thinner than glass because it has a higher tensile strength. It will be appreciated, however, that the device is not limited to the use of mica in the window since, for certain purposes, other material impervious to moisture, such as aluminum, may be used.

Having thus described our invention, we claim:

1. A tube of the class described comprising a spun copper chamber'having a flange at one end, aconnector sealed in the other end and including an insulating member, a hollow metal connector extending through said insulating member, a

ycenter electrode carried by said insulating memb-er and extending into said chamber, window means for said flange and for closing the other end of said chamber comprising a mica disc, cushion means disposed on each side of the .mica disc, a flanged cup embracing the cushion means and the mica disc, cement means for engagement with said flange and said cup and the edges of the mica disc and cushion means.

2. A tube of the class described comprising a spun copper chamber having a ange at one end, a connector sealed in the other end and including an insulating member, a hollow metal connector extending through said insulating mica disc, cushion Vmeans disposed on each side Number of the mica disc, a flanged cup embracing lthe cushion means and the mica disc, cement means for engagement with said flange and said cup` and the edges of the mica disc and cushion means, and clamping means having a window formed therein surrounding said flange and said disc and cushion means.

3. A tube of the class described comprising a spun copper chamber having a flange at one end, a connector sealed in the other end Vand including an insulating member, a hollow metal connector extending through said insulating inember, a center electrode carried by said insulating member and extending into said chamber, window means for said flange and for closing the otherend of said chamber comprising a mica disc, cushion means disposed on each side of the mica disc,V a ilanged cup embracing the cushion means and the mica disc, cement means for engagement with said flange and said cup and the edges of the mica disc and cushion means, and clamping means, a threaded cup having a window formed therein surrounding said flange and said disc and cushion means, and threaded means for engaging said ilange and said cup.

JOHN A. VICTOREEN. ROGER W. BARTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Lockwood Nov. 1, 1881 Edison f June 30, 1891 Danielson May 23, 1939 Friedman July 12, 1949 lOTHER REFERENCES Copp and Greenberg, Review of Scientific 1nstruments, vol. 14, No. '7, July 1942,7pp. 205 and

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