Патент USA US2121591код для вставки
2,121,591 R K. GESSFORD ET AL GEID GLOW TUBE WITH ZERO TEMPERATURE EFEEcT' ' Filed Jan. - 10, 1936 O00 (000 O00 (O00) (1)0) 0(00 0 ‘011,00 U ‘WITNESSES: ; WMM a " '1 f ' I, l ENVENTORs. Dewey D; Know/e5 and ‘19055 K Gressford. 21,121,591 Patented June 21, 1938 UNITED STATES PATENT‘ OFFICE ' '7 2,121,591 GRID! cnovvv TUBE‘ WITH ‘ZERO TEMPERA ‘TUBE EFFECT ' Ross K. Gessford and Dewey D'. Knowles, Wil . kinsburg,,Pa., assignors to Westinghouse Elec tric & Manufacturing Company, East Pitts; burgh, Pa., a corporation of Pennsylvania Application January 10, 1936, Serial 'No. 58,526 (01. 250--27.5) ' 7 Claims. This invention ‘relates to'gas ?lled discharge for grid control of currents. It is an object of this invention to increase 5 the life of tubes and particularly to avoid the limitation upon the life of the tube which can be attributed to the clean-up action of the dis ' ' glass. _ ‘ ‘ It is a further object of this invention to pro ' 9 It is a iurther'object'oi thisinventionv topro vide a shield in the form of a'cylinder surround ing the anode and cathode and having a parti It is a further object of this invention to-prO vide such a grid with the part next to the anode imperforate, and the remainder of the'grid con 25 30 V 1 It is a further object of‘this invention to pro vide a structure of the class described in which the cathode is situated between the partition across the cylinder and a radiation shield sup ported from the press. It is a further object of this invention to provide an atmosphere free from mercury in which the discharge occurs. 5 " It is a further object of this invention‘ to pro vide in a gas-?lled tube free from mercury a cor 35 rectly chosen pressure whereby sputtering'is pre vented and yet grid control is permitted; In a tube of this sort with the pressure so chosen,the life of the tube is greatly enhanced. \ It is a further object of this invention to pro 40 duce a device of the class describedin which the tube characteristics shall be constant ‘at ‘all ordinary temperatures. 1 -' - ' It is a further object of this invention to pro vide a discharge tube ?lled with ‘helium. 45 i It is a further object of this invention to pro vide a structure whereby the gas pressure can be increased above that used in conventional struc tures still maintaining the control voltage limit and giving lower tube drop, and increased life. 50 Other objects of the invention and, details of the'structure will be apparent from the following description and the drawing, in'which ' ' > Figure 1 is a vertical sectional view through the device, and 55 ing a press 2 in which are several standards. The _‘ speci?c illustration discloses three of these stand- @5' ards although more or less may be provided. The upper partof the press has a ?ange 4 which across the press to the leads. I} _ The cathode 1 consists of a coiled metallic rib- 10 bon coated with emissive oxides. It is supported between two of the standards, 8 and 9, which ex~ tend through the press to external conductors. These standards are welded to the ends of the w ribbon and form the conductors to the heating 15 circuit. The standard 9 is connected by means of a welded sleeve H] to a radiation shield II. The standards 8 and 9 extendthroughperforations in the shield .l I, the sleeve Ill being welded to the radiation shield H at one of these perforations. 20 20 tion separating the anode and the cathode. ? taining many perforations. > The device comprises a glass envelope I hav affords a lengthy leakage path for any leakage vide a shield surrounding the dischargepath and 145' acting to prevent ionization of the gas outside of the shield. ' ~ It is a further object of this invention to so 16 arrange the electrodes that no discharge will occur through the parts of the tube adjacent to the I Fig. 1. 7 devices of the sort used to rectify currents and charge. . in a vertical plane at right angles to that of " Fig.2 isla similar view,.the section being taken The radiation shield is thus maintained at the potential of one end‘ of the‘ cathode. The anode is supported at the other endof the envelope by means of a press l5 through which a standard It extends. The standard‘ 16 is sur- 25 rounded by a glass skirt H which is continuous with the press I5 and forms a lengthy path pre venting leakage'to or from the anode l8. Exter nal of the envelope the standard It is united with a cap I9 affording convenient connection 30 means for the anode circuit. . The anode I8, the cathode 1 and the radiation shield l l are surrounded by a cylindrical grid or shield 20. A partition 2! is secured across the cylinder 20 between the anode l8 and the cathode 35 l. The partition 2| is foraminate, the foramini having diameters of about one-tenth of an inch. For certain purposes it may be desirable to make the cylinder 20 foraminate also, although a con struction in which the portion above the partition 40 ' 2| is devoid ofcperforations, or alternatively in ' Which the entire cylinder '20 is imperforate is within the scope of my invention. No mercury is left in this tube when it is ?nished. It is ?lled with a noble gas of light 45 . speci?c gravity, such as argon, neon or helium. Best results have been obtained with helium. Heretofore the pressure of the gas in the ?nished tube is about 0.4 millimeter of mercury at work ing temperature but with the new style of grid it 50 can be increased to 1.75. , In the operation of the device, when the oath ode has been heated by current through 'the leads 8 and 9 and a potential is applied between the anode l8 and the cathode, a discharge is set 655 2 . 2,121,591 up which extends from the anode 18 through the perforations in the grid to the cathode 1. lium that a pressure of 1.75 mm. of mercury No discharge occurs in the space outside of the grid, although such discharge can occur with a grid foraminate over its whole extent. When If a higher pressure of helium is used the con trol by the grid at 750‘volts on the anode is lost. We do not desire that the speci?c description this tube is operating, a glow may be observed in the space between anode and cathode, but it may and illustration of one form of our device should limit us to that speci?c form,. but we recognize be seen that no such'gloW occurs outside of the grid 20. 10 gives good results with the grid herein described. that many modi?cations will occur to those 7 skilled in the art. No limitation is intended ex The reason for this we are not at present able cept those required by the prior art or expressed 1O to state with certainty, but it is our belief that l in the claims. the metallic body 20, in addition to its action We claim as our invention: as a grid, acts also to absorb whatever ions col 1. In a gaseous discharge device, an envelope, lide with it and thus prevent the formation of a cathode and an anode therein, a cylindrical 15 an are outside of it. The charges thus intro grid'surrounding said anode and cathode, and 15 duced into the cylinder 20 are conducted by the electrically separate therefrom and a partition connector 23 and over the lead 24 to whatever across said grid separating said anode and cath external connection is provided. For many pur ode, the portion of the cylinder on the anode poses, the external connection is to one end of side of said partition being imperforate and all 20 the cathode. We believe that the electrons from the rest of said grid being foraminate. the cathode 1 will not penetrate the openings . 2. In a gaseous discharge device, an envelope, in the grid in su?icient number to set up ioniza a cathode and an anode therein, a cylindrical tion in the gas except in the line between the grid surrounding said anode and cathode and a cathode and the anode where the electrons perforated partition across said grid separating 25 possess a high velocity. The ions which they said anode and cathode, the gaseous atmosphere 25 thus create by ionization of the gas neutralize within said envelope consisting of helium at a the space charge and provide ready formation pressure of the order-of 1.75 mm. mercury. for an are through the holes in the partition 3. In a gaseous discharge device, an envelope, 2|, but only a little ?eld from the anode l8 ex a cathode and an anode therein, a cylindrical 30 tends into the space exterior to the cylinder 20 grid surroundingsaid electrodes and electrically and, therefore, no such velocity can be given to separate therefrom and a perforated partition the electrons which tend to emerge from the across said grid separating said anode and cath cylinder. We do not wish to be limited by this ode, the cylindrical portion of the grid being explanation because we are unable as yet to be imperforate and extending past the anode into 35 sure why the discharge does not occur outside close proximity with the glass. 35 of the cylinder 20. 4. A gas discharge device comprising an en When the gaseous discharge tubes known velope containing’ an anode and a cathode, a heretofore are working, the discharge produces ?lling of a gas which is non-lique?able at ordi a diminution in the pressure of the gas. ' When this effect has proceeded so far that not suf?cient gas remains to supply ions, ionization ceases and the life of the tube is terminated. We believe that this effect of the discharge upon the gas is most rapid when the discharge takes place 45 near the glass. We have observed but are not yet able to explain that the clean-up effect of the discharge upon the gas does not occur when the discharge does not contact the glass of the envelope. We, therefore, have provided that the 50 cylinder 20 extends beyond the anode l8 into close proximity with the envelope I. The anode I8 is unable, therefore, to have an arc extend ing around the end of the cylinder 20 and through the holes in the cylinder 28 to the oath 55 ode 1. There being no discharge in proximity to the glass, there is little or no clean-up effect noticed. The tube, therefore, can last inde? nitely. _ ~ When desired the shield is connected through nary room temperature and pressure, the pres sure of said gas being of the order of 0.4 mm. 4.0 to 1.75 mm. mercury, and a‘ conductive member surrounding said anode and cathode and ex tending into close proximity to said envelope in the region of the anode, said-member having a perforated partition extending across its in 45 terior to separate said cathode from said anode. I 5. A gas discharge device comprising an en velope containing an anode and a cathode, a ?lling of helium at a pressure of the order of 1.75 mm. mercury, and a conductive member 50 surrounding said anode and cathode and ex tending into close proximity to said envelope in the region of the anode, said member having a perforated partition extending across its interior to separate said cathode from said anode. 6. In a gas discharge device, an anode, a cath ode, and a conductive member surrounding said anode and cathode and having a perforate por tion transverse to the region between them, said member being foraminate throughout the por 60 the lead 24 to an external source of potential. The potential of the grid may be'varied accord- ' tion nearest the‘cathode and imperforate near ing to any desired ?ow. One well known flow which we have found useful is to keep the grid su?iciently negative to prevent an are forming 65 until a predetermined point in the cycle of al— ternating potential is reached and then permit it to become su?iciently positive to permit an arc to form. The are will then continue until the anode potential has become zero. 70 If the tube be ?lled with mercury-free gas the pressure may be so high that no potential on the grid will prevent the are from forming. If the gas pressure be too low sputtering at the cathode will be so rapid that the life of the tube 75 is shortened thereby. We have found with he the anode, the imperforate portion extending beyond the' anode. 7. In a gas discharge device, an envelope, an anode, a cathode, and a conductive member sur 65 rounding said anode and cathode and having a perforate portion transverse to the region be tween them, said member being foraminate throughout the portion nearest the cathode and imperforate near the anode, the imperforate portion extending beyond the anode into close proximity to the envelope. ROSS K. GESSFORD. DEWEY D. KNOWLES‘.