US2518090A

US2518090A - Electron discharge device

Info

Publication number: US2518090A
Application number: US46122A
Authority: US
Inventors: Stivin Jiri
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-08-26
Filing date: 1948-08-25
Publication date: 1950-08-08
Anticipated expiration: 1967-08-08

Description

Aug. 8, 1950 J. STlVlN ELECTRON DISCHARGE DEVICE FiI ed Aug. 25, 1948 v y 2 z w a Q g g 1 a z vfi 5 k 5 MW 0 Z 5 IYWIIIA Q j F Patented Aug. 8 1 950 ELECTRON DISCHARGE DEVICE J ii-i Stivin, Rychnov, near J ablonec nad Nisou, Czechoslovakia Application August 25, 1948, Serial No. 46,122 In Czechoslovakia August 26, 1947 The present invention relates to improvements in electron discharge device and is an improvement of the invention according to U. S. Patent 'No. 2,466,565 issued April 5, 1949, which discloses an electron discharge device with an outer anode, wherein the cathode and grid leads are placed in leading-in members, mounted on the cover of the. discharge or anode vessel and made at least partially of glass tubes, insulating the leads from the anode which forms the discharge vessel, said leading-in members being enclosed within a container provided above the discharge vessel itself and filled with an insulating liquid such as oil.

The present invention relates to improvements in, or modification of, the above electron discharge device. According to one feature of the present invention the lower metal portion of the leading-in members, provided on the cover of the anode vessel, are made integral with the cover of the same, preferably by a pressing operation; the connection of the upper edges of the said metal portion with the lower ends of the glass portions of the leading-in members may be carried out in the same way as the connection of the upper ends of the glass portions with the upper metal caps of the said leading-in members, i. e. by means of high frequency sealing or fusing. In this way the necessity of providing a sealing of the contact surfaces on the lower ends of the leading-in members and on the cover of the anode vessel is dispensed with and the entire sealing of the electron discharge device is limited to the sealing between the cover of the anode vessel and the upper edge of the vessel. Preferably a steel sealing ring is employed for carrying out the sealing operation. In this way an easy dismantling of the electron discharge device is possible.

According to a further feature of the invention recesses in the form of a shallow spherical sector are provided at the lower side in the bottoms of the upper caps of the leading-in members, arranged on the cover of the anode vessel, said recesses serving to receive annular washers secured at the ends of rod-like carriers of the filament and grid, the upper side of the Washers having a corresponding spherical formation. The upper ends of the carriers are secured to the bottoms of the metal caps by means of rings or annular gibs which are slid on the rod-like carriers and fastened by means of a number of circumferentially spaced screws, screwed into threaded holes provided in the bottom of the metal caps around the said recesses. In this way a perfect and rigid connection is achieved, the spherical 3 Claims. (01. 250-275) formation of the contacting surfaces assuring automatic centering of the various parts. The ends of the molybdenum carriers pass preferably through the washers provided thereon and are ground together with the upper side of the washers to the spherical shape so that a direct contact between the end of the molybdenum carriers with the bottom of the metal caps of the leadingin members is achieved. According to a further feature of the invention the metal cup mounted at the end of the grid between the end of filament and bottom of the anode vessel, is provided with perforations so as to serve as a portion of the grid, increasing thus the operative surface of the anode by the area of its bottom.

By the said provisions an extraordinary simplification of manufacture and assembly of the electron discharge device is achieved. The container of the discharge device consists substantially of the anode vessel and its cover, provided with leading-in members, the metallic lower portions of which are made integral with the cover. The connection of the said metal portions with the glass portions of the leading-in members, as well as the connection of the glass portions with the metal caps is preferably carried out by a high frequency sealing or fusing operation. The container of the discharge device consists, therefore, of an anode vessel and cover with leading-in members. The inner system of the discharge device consists of a grid, carried by molybdenum carriers, and filament, carried by molybdenum carriers as well. In consequence of the above described arrangement the grid with its carriers and the filament with its carriers may be fully assembled and then simply fastened by screwing the same to the upper portion of the discharge device container, so that the two electrodes are carried by the cover of the vessel. The cover, together with the grid and filament is thenin serted into the anode vessel, while the contact portions between the anode vessel and the cover are suitably sealed.

The described simple assembly operation makes it possible to easily remove impurities from the inner surface of the glass portions of the leadingin members, which impurities are deposited thereon during the heating of the electron discharge device carried out for the purpose of expelling the occluded gases. The discharge device may be assembled and its filament and grid subjected to heat treatment in a known manner under a simultaneous evacuation of gases. During this operation the evaporated metal particles of the "like carriers or leads.

electrodes condense on the cooler portions, 1. e. on the anode, cover and inner surface of the glass portions of the leading-in members. Such particles could be objectionable in the leading-in members, as they would reduce the insulating resistance between the electrodes. Owing to the possibility of an easy dismantling of the discharge device it is, therefore, possible to remove the cover after the degassing operation of the filament and grid has been completed and to clean the soiled surface of the glass leading-in members with a suitable chemical solution. In the final assembly of the discharge device a new clean anode is used as the proper anode, whereas the anode which has been soiled in the degassing operation is used for degassing of other discharge devices, so that the so called soiled anode serves only for the manufacture of discharge devices.

The individual branches of the filament are secured by their upper ends to two concentric rings, made integrally with the molybdenum rod- The upper ends of the individual branches of the filament are secured to the'rings by passing the ends of the wires of an electron discharge device carried out according to the invention will now be described with reference to the accompanying drawing wherein:-

Fig. 1 represents in longitudinal section the j.

electron discharge device alone without the outer cover or cooling jacket,

Fig; 2 shows in a cross-sectional view on a through small holes drilled in the rings, and the 4 glass-tubes 8 to all lower portions I0, which are integral with the cover 3, because there would not be space enough for instance for sealing by means of a gas flame.

The cover 3 is further provided with an evacuating tube which may consist of a copper tube 88 secured to the cover. The end of the tube 88 carries a glass tube 8! sealed thereon, the glass tube 8| being adapted to be closed or sealed in the usual way after the discharge device has been evacuated.

' The upper bottoms of the metal caps 6 consist, as apparent in particular from Fig. 2, of relatively thick copper discs 5| provided at their top with extensions 52 carrying a screw thread serving for the, attachment of the current supply conductors. The lower sides of the bottom 5| are provided centrally with shallow recesses 53 having the shape of a. shallow spherical sector. The upper ends of the grid and filament carriers 54', consisting of molybdenum rods, areprovided with annular-copper washers 55; the upper ends of the molybdenum carriers are rigidlysecured in the central bore of the washers. The-upper side of the washers 55 is ground together-"with the molybdenum-carrier- 54 to the shape'of a spherical surface'coinciding with the spherical recess 53. The rod-like carriers 54 are-secured to thebottoms 51 of the cup 6 by means of annular gibs or rings 55 slid over the carrier 54 and providede. g.- with three circumferentiall-y spaced holes serving for the reception of screws 51 which are screwed into threaded holes 58 in the bottom 5! of the metal cap 6; I r

In assembling the discharge device the cover I 3 with the leading-in members is placed inreflarger scale the manner of securing the ends of p p the rod-like carriers to the bottoms of the upper metal caps of the leading-in members,

Fig. 3 shows diagrammatically the method of securing the upper ends of the individual filament branches to the carrier of the filament and i Fig. 4 is a modification of the arrangement on Fig. 3.

Figure 5 is a top view of the device shown in Fig.- 1.

As shown in Fig. 1 the electron discharge device consists of an anode or anode-vessel I, closed on top by a cover 3 provided with leading-in members. Each such leading-in member consists of a lower metal portion 10, central glass portion 8 and upper closing metal cap 6; This arrangement is similar to the arrangement according to U. S. Patent No. 2,466,565, issued April 5, 1949.

According to the present invention the metallic portions 10 of the leading-in members are made integral with the cover 3. The cover, together with the lower portions of the leading-in members is preferably pressed from a copper sheet disc which renders its manufacture extremely simple. The glass portions 8 may be made of glass tubes, if required with walls of considerable thickness,

said tubes being closed on top by metal caps 6 sealed to the glass tubes. The sealing of the lower ends of the glass tubes 8 to the upper edges oftthe metal portions l0 may be carried out by ahigh frequency heating process. It is only this process which. makes possible .the sealing of the versed position on a suitable support, e. g. table, whereupon the filament and then the gridare secured thereto by introducing their carriers 54 into the corresponding leading-in members, while in their reversed position. By means of a long screwdriver the screws 51, inserted beforehand are screwed in, so as toclamp the washer 55-at the end-of-the carrier 54between the bottom 5| and ring 56. This arrangement allows compensation of deviations, ifany, in addition to-an extremely simple way of fastening, while owing to the-arrangementof the spherically shaped contactsurface between the bottom 51 and washer 55 the individual carriers areautomatically centered. The upper end of the carrier 54 passing through the washer 55, a directcontact between the carrier 54- andbottom 51 is achieved. The filament conductors, to which the individual U-shaped portions of the filament, extendinginto the anode vessel l, are secured; have intheir lower portion the shape of two rings 61 and- 62 mounted one inside the other. One end of" each filament wire 63is connected with the ring 6| and: the other with the ring 62 so that all filament wires 63-are connectedinparallel. The upper ends of the wires63 are secured to rings- 6l and 62 by being passed through holes drilled'in the said rings. The upper ends of the wires 63, protruding above therings BI and 82 are swaged into small balls 64-, to secure the wires 63 tothe rings 5| and 62. The upper portions of the wires, con nected with the inner ring 62 are bent inwardly at an angle and-their end portions are bent back again into vertical direction according to Fig.3, or the holes inthe inner ring 62 may be drilled at an angle so as to receive the wires according to; Fig. 4.

The fastening .ofthe filament wire 63 to" the carrying rings it and 62 is. extremelysimple whlle permitting easy replacement of the damaged filament wire, as the required balls 64 may be simply ground away and a new wire 63 secured in a similar way.

The grid is made of a wire 30, wound in a helix or in the shape of wire rings around axially extending carrying wires 3|. The carrying wires are secured on top to a ring H and at their lower end to an annular rim 12 of a cup 13. The ring I! is secured to one or two grid-carriers consisting of molybdenum rods. The lower cup 13 has usually a full bottom and serves to close the lower end of the grid. According to the present invention the cup is perforated, as shown in the drawing, or its bottom is made of a wire mesh, preferably of wires of the same thickness and arranged at the same distance from each other as in the other portions of the grid, while the distance between the cup and the bottom of the anode and between the cup and the lower portion of the filament is equal to the distance between the proper grid 30 and the annular portion of the anode and the axial portions of the filament wires 63. The cup 13 forms therefore a portion of the grid so that the operative surfaces of the grid and anode are thus increased by the said cup and the bottom area of the anode.

In assembling the electron discharge device according to the present invention the cover 3 with the leading-in members with filament and grid carriers, secured. in the caps 6, which have already been assembled, is inserted into an auxiliary anode which is similar to a normal anode. The sealing operation between the rim of such anode and the rim of the cover 3 may be preferably carried out by means of a sealing ring 82.

After the discharge device has been assembled and evacuated, it is connected into suitable current circuits which bring the electrodes to a suitable temperature while further evacuation takes place. In this way the degassing of all components of the discharge device is achieved. During this process metallic articles are, however, released, soiling various portions of the discharge device including the anode and the upper portion of the container of the discharge device. According to the invention the electron discharge device is dismantled after the degassing operation, its glass portions as well as carriers etc. are chemically cleaned by a suitable chemical substance and the whole system is then inserted into a new clean anode I, whereupon the electron discharge device is finally closed and evacuated, during which operation the anode is degassed.

The soiling of the auxiliary anode is not objectionable and such anode may be used for the degassing of further discharge devices. If required it may also be cleaned from time to time.

While I have disclosed the principles of my invention in connection with one embodiment, it will be understood that this embodiment is given by way of example only and not as limiting the scope of the invention as set forth in the appended claims.

I claim:

1. An electron discharge device comprising in combination, a closed anode vessel having a top wall; inlet openings in said top wall of said anode vessel; tubular leading-in members extending upwardly from said anode vessel and each including a metal lower portion being integral with said top wall of said anode vessel and surrounding one of said inlet openings, an intermediate glass portion having its lower end connected to the upper edge of said metal lower portion and a metal cap having its lower edge connected with the upper end of said intermediate glass portion, each of said caps having at its lower side a recess shaped as a shallow spherical sector; cathode and grid leads passing through said tubular leadingin members and through said inlet openings into said anode vessel; annular washers electrically connected, respectively, to said cathode and grid leads, the upper side of each of said washers having a convex spherical surface, corresponding to said recess in the lower side of said metal upper caps, each of said washers being seated in one of said recesses; annular gibs, each of said gibs being slid on one of said cathode and grid leads; a plurality of circumferentially spaced screws, screwed into threaded holes of each of said metal caps around said recess and connecting, respectively, said gibs to said metal caps; and an upper vessel surrounding said tubular leading-in members and extending upwardly from said anode vessel, the bottom edge of said upper vessel being filled at least partly by an insulating and heat conducting liquid.

2. An electron discharge device as claimed in claim 1, each of the upper ends of said cathode and grid leads passing through one of said washers in order to obtain direct contact of said lead with the bottom of one of said metal caps.

3. An electron discharge device comprising in combination, a closed anode vessel having a top wall; inlet openings in said top wall of said anode vessel; tubular leading-in members extending upwardly from said anode vessel and each including a metal lower portion being integral with said top wall of said anode vessel and surrounding one of said inlet openings, an intermediate glass portion having its lower end connected to the upper edge of said metal lower portion and a metal upper cap having a lower ed e connected with the upper end of said intermediate glass portion; cathode and grid leads passing through said tubular leading-in members and through said inlet openings into said anode vessel electrically connected with said metal upper caps of said tubular leading-in members; two metal rings of diiierent diameters being secured, respectively, to the lower end of one of said cathode leads; one of said rings being arranged inside the other; a cathode including a plurality of U-shaped wires; one of the upper ends of each of said wires being secured to one of said rings and the other of the upper ends of each of said wires being secured to the other of said rings, said rings having holes traversed by the upper ends of said wires, the ends of said wires protruding above said rings being swaged into small ball-shaped members; and an upper vessel surrounding said tubular leading-in members and extending upwardly from said anode vessel; the bottom edge of said upper vessel being sealed to the anode vessel and said upper vessel being filled at least partly by an insulating and heat conducting liquid.

Jrni STIVIN.

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

UNITED STATES PATENTS Number Name Date 2,079,137 Varian May 4, 1937 2,317,442 Chevigny Apr. 27, 1943 2,408,239 Spencer Sept. 24, 1946 2,431,114 Scullin Nov. 18, 1947 2,452,401 stivin Oct. 26, 1948 2, ,565. Stivin Apr. 5, 1949