Патент USA US2114885код для вставки
April 19, 1938. E. F. LOWRY 2,1 14,885 GASEOUS DISCHARGE TUBE Filed Aug. 26. 1956 WITN ESSES: ~ \ INVENTOR Evy/'27 Flow/)4 W% BYw VATTORNE ‘ Patented Apr. 19, 1938 2,114,885 “orriis I 23143851.? GASEOUS'DISCHA‘RGE TUBE Erwin F. 'Lowry, Batavia, Ill., assignor to West inghouse Electric & Manufacturing Company, East Pittsburgh, Pa, a corporation of Penn Sl’lvania ' Application August 26, 1936, Serial No. 97,974 6’Clai‘m’s. My invention relates to discharge tubes and (01.‘250-275) ' um and ‘strontium oxide, such as is disclosed in especially to such tubes having a gaseous atmos-v phere therein from a vaporizable substance. An object of the invention is to lengthen the discharge path between the cathode and .the anode so that material from the cathode will not sputter on the anode and create back emission. Another object of the invention is to decrease the tendency of such tubes to vary their charac 10 teristics with a change in the ambient tempera ture. ‘One of the common forms of tubes having a vaporizable substance for creating a gaseous at mosphere is that of the hot cathode mercury va 15 por type. The gaseous atmosphere is provided by a globule or more of mercury. 20 25 30 35 40 Changes in tem perature of the device result in a change in va por pressure with the result that the characteris tics of the tube are changed. One cause of this variation vapor pressure is that the globule of mercury is generally at a position in the bottom portion of the tube far removed from. the dis charge path between the cathode and anode with the result that the temperature around the bot tom portion of the tube will affect the vapor pres sure. With diiferent ranges of temperature, the control characteristics of the tube, for example, Will vary by several volts. It is one of the speci?c objects of my invention to provide means for re?ecting heat from the cathode onto this mercury so that the mercury may be speedily vaporized when the tube is put in operation and also that changes in the ambient temperature will have a less percentage effect on the temperature of the mercury vapor. Other objects of my invention will become evi my Patent 1,968,608, issued July 31, 1934. An anode i7 cooperates with this cathode and is pref erablylocatedat the upper end of the tube with a leadsupport l8 passing through this upper por tion of the tube. . For the various objects of my invention hereto fore mentioned, I provide a member 20 preferably having a bulge 2| towards the anode and located in What would be normally the direct discharge 10 path between the cathode and anode. This cen tral portion 2| of the member is imperforated so‘ that material on the coating of the cathode l4 cannot sputter onto the anode and cause back emission. The cathode I4 is located within the 15 inner portion of this bulge 2|, so that the electron path Will necessarily have to be a round about path to the anode |'|. While the bulge 2| may be of any suitable con ?guration, as far as preventing sputtering on the 20 anode and for lengthening the discharge path yet for the purpose of bringing the mercury vapor speedily up to the desired pressure, I prefer to curve the inner portion 22 of this member in a parabolic or spherical shape. The purpose of 25 curving this member is to provide a surface that will re?ect the heat from the cathode to the pock et l3 containing the condensed mercury. The lines 23, 24, 25, 26, 21, 28, 29, and 3|] indicate the paths of heat waves from the cathode that are 30 reflected to the surface of the mercury in order to aid in the vaporization of the same. Materials similar to mercury may, of course, be used. In some devices light sensitive mate rials may be desired and my invention contem 35 plates providing a re?ecting means such as the dent from the following detailed description taken in conjunction with the accompanying drawing, member 2| for re?ecting the light from the hot cathode onto such substances. In other words, in which: my invention is suitable for the re?ection of radi ant energy Whether this energy be‘ heat or light. 40 The member 22 may act as a grid or control member by utilizing one of the supporting mem bers 3|, 32 as a lead for the application of any The ?gure is a view in cross section of a tube disclosing a preferred embodiment of my inven tion. The tube M has the usual reentrant portion | 1 comprising a press l2 surrounded by the annular 45 trough IS. The trough 53 provides a pocket for the vaporizable substance such as the mercury I5. This mercury may, of course, be one or more globules. I have disclosed the trough I3 as hav ing this pocket, but it is apparent that other types 50 of pockets may be utilized for holding the con densed metallic liquid. A cathode I4 of the type adapted to be heated is supported on the press by the lead-in supports Hi. This cathode may be of any suitable type, but I prefer to utilize the edge 55 wise wound helical ribbon type coated with bari desired potential thereto. 45 The outer portion of the member 2|! may be perforated, as shown at 33, for the passage of electrons and positive ions therethrough. It Will be noted that the electrons from the hot cathode will have to pass downward to the holes 33 and 50 then back up to the anode IT. This reverse path of the electrons will prevent any sputtered material from the cathode reaching the anode IT. The member 2|] will also act as a very effective radiation shield for the heat energy vproduced by 55 2 2,114,886 the cathode and will keep the metallic liquid in the lower portion of the tube suitably vaporized. Although I have shown and described a certain speci?c embodiment of my invention, I am fully aware that many modi?cations thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art. I claim as my invention: 10 1. A discharge tube comprising a container, a cathode adapted to be heated, an anode coop erating with said cathode, a vaporizable medium in said container having a position, when not vaporized, away from direct radiation paths from 15 the major portion of said cathode, and means re?ecting radiant energy from said cathode to said vaporizable medium. 2. A discharge tube comprising a container, a press, a cathode adapted to be heated supported 20 on said press, a pocket beside said press, a vaporizable medium in said pocket, and means for reflecting radiant energy from said cathode to the vaporizable medium in said pocket. 3. A discharge tube comprising a container, a. re-entrant portion of the container having a pocket therein, a vaporizable medium in said pocket, a cathode supported on said reentrant portion and means re?ecting radiant energy from said cathode to the vaporizable medium in said pocket. 4. A discharge tube comprising a container having a cathode and anode, a member extending across the container between said cathode and anode and having a bulge toward said anode, said cathode being within the bulge part of said mem ber and a connection for the application of elec 10 trical potential to said member. 5. A discharge tube comprising a container having a cathode and anode, a member extend~ ing across the container and having a bulge to ward said anode, said cathode being within said 15 bulge, the portion of the bulge directly between said anode and cathode being imperforate. 6. A discharge tube comprising a container having a cathode and anode, a member extend ing across the container and having a bulge to 20 ward said anode, said cathode being within said bulge, the portion of the bulge directly between said anode and cathode being imperforate the outer portions of said member having perfora tions. 25 ERWIN F. LOWRY.