US1931831A - Electron valve with subdivision of the system supports affording heat protection - Google Patents

Description

Oct. 24, 1933. ROMHILD ELECTRON VALVE WITH SUBDIVISION OF THE SYSTEM SUPPORTS AFFOHDING HEAT PROTECTION Filed Aug. 25, 1928 Patented Oct. 24, 1933.

ELECTRON VALVE WITH; SUBDIVISION or I THE SYSTEM SUPPORTS- AFFORDING I HEAT PROTECTION Edgar-Riimhild, Berlin, Germany I Application August 25, 1928, Serial No. 301,966, r and in Germany August 31, 1927 Claims. (01. 250-275) In electron valves the leads to the different electrodes arranged within a valve or the leads to the different electrodes forming part of one system of electrodes are generally held in the desired position by passingthem through an insulation piece which may consist of a small glass rod-,- the different conductive leads thus being arranged (fused) in close proximity with one another in a uniform insulation compound.

0 Generally insulation pieces are made of such material as glass etc.which at normal room temperature affords suchgood insulation that disturbing current transitions from one electrode to other ones are avoided. It has however been found that the cathode being heated to the operation temperature, oftensuch a lot of heat is developed that the glass rod is heated to a rather high temperature of about 250 to 400 degrees. The insulation power of the glass at this temperature being essentially. diminished, disturb- I ances are produced by leakage currents between the single leads. These kinds of disturbances ought to be particularly avoided becausethey are causing a detrimental variation of the value of the grid potential. 'Said variation of the grid potential, being able to disturb wholly the good working the valve, especially if the electrode systems concerned are connected to form a resistance coupled amplifier. It has been proposed .to arrange inside the glass,

supports between the leads special protecting electrodes which are connected with an auxiliary potential which is nearly as large as the potential of that lead which shall be protected. i An object of my invention is an electron valve in which the glass support is subdivided in such manner as to prevent leakage currents between the single leads.

A further object of my invention is to provide several supports for the different leads, said supports being or being notjoined witheach other by means ofauxiliary glass rods, wires or the like. w

A still further object of my invention is to pro another support for the anode and the grid leads.

.Stillfurther objects of my invention will be best understood with reference to the description and the drawing. v

Referring to the accompanying drawing Fig. 1 is a perspective view of an electron. valve in which according tothe invention two glass rods are provided, and the electrode system of which contains a directlyheated incandescent cathode.

' Fig. 2, and

vide one support for the cathode leads and.

- Fig.2 is a side elevational view of a valve, which essentially. corresponds with the valve shown in Fig. 1, the electron system of which contains yet an indirectly heated cathode. r 1 V Fig. 3 is an elevational view of a valve in which the glass support is subdivided according to' the so invention in three independent parts.

Fig. 4 is a plane view taken on line C-C in Fig. -2.

Fig. 5 is a plane view taken on line BB in I Fig. 6 is a plane view taken on line A-A in 1 is the anode which, for instance, may have, the form of a cylinder and may be provided with a sheet edge 2 to which two wire supports 3 and 4 are attached the terminals of which are jointly held in the glass rod 5. The wire 3 thusmerely serves'for fastening while the wire 4 serves as the lead of-the plate. voltage. The controlelectrode (thegrid) '6 is held by the wire supports '7 and 8, 1

ct which '7 in its turn serves merely as a mechanical support while 8 serves as the lead of the grid voltage. The four wires 3, 4, 7 and 8 are held'in the glass rod 5. Below the rod 5 there is a further rod 9 inside of which the two leads 10 and 11 are fastened-1 .which carry the incandescent cathode "12 and. which serve at the same time as leads of the heating current.

m the arrangement according to Fig. l the glass rod 9 is subjected to fairly considerable heating especially in the spots close to the. wires 10 and 11. The resistance, which still has a value ofmany ohms produces'an inconsiderable currentloss between the two seals 10 and 11. On the other handa voltage arises between the wires 3 and 4 connected with the anode and between the wires 7, and 8 connected with the grid and likewise inside rod 5. The excellent insulation which is absolutely necessary between these electrodes and which would already fail if the contact resistance would sink to an amount of several megohms, is in the arrangement described jeopardized in no respect, since the temperature of the glassrod 5 remains much below the temperature at which a noticeable conductive increase 100 may take place, the incandescent wire conducting its heat not to thisglass rod 5, but to theother glass rod 9'. In Fig. 2 is shown in what manner the arrangement according to Fig. 1 may be supplementedfor obtaining an indirectly heated cathode: the cathode 13 which may be constructed as a thin tube surrounding the heater, is connected by means of the wires 14 and 15 with the glass rodi). These wire leads, as is not particularly shown in Figure .2, are run outside the. supply area in order to avoid the exertion of an influence by the leads to the other electrodes. Wire 14 again ends at the glass stick 9 while wire 15 serves as the cathode lead.

If the two glass beads 5 and 9 of Fig. 1 are not sufficiently stable it may be advisable to use additional supporting wires 16 and 17 I In the case of multiple valves several electrode systems according to my invention may according to Fig. l be arranged inside one valve when it is not always necessary for all electrode systems to be constructed. In valves withseveral voltage amplification stages and one power amplification stage it may be advisable on the contrary, to protect more particularly the voltage amplification stages, which are especially sensitive to insulation disturbances, in the manner described and illustrated in Figs. 1 and 2.

Fig. 3 discloses a further embodiment of my invention in which the lead in wires to the indirectly heated cathode are supported by. a particular glass rod. Besides glass rod 5 for anode and grid and the glass rod 9 merely supporting the heating wire, a special glass rod 18 is provided which supports the cathode bilaterally and which by wires 19, and 20 is mechanically con nected withthe rod 9. 22 is the flare tube of the valve through which the wires 4, 8, 10, 11, and 15 are passed to the outside.

My invention is not limited to the embodiments as shown in the figures. Whilst hitherto for every single electrode system there was merely a simple undivided and generally cylindrically constructed support, the support according to my invention is subdivided in any manner in order to protect the parts which are sensitive to insulation damages, against leakage currents. With multiple valves my invention may also be carried out in such manner that several electrically or therrnotechnically equivalent leads of diiierent electrode systems are held at one support: for instance the incandescent wires of two voltage amplifying electrode systems may be supported by one mutual pedestal.

I claim:

1. An electron discharge device comprising an evacuated vessel, a stem, an electrode system consisting of a plate, a grid and an electron emitting source, current supply-wires passed through said stem to said electrodes, support-wires for said electrodes, a supplemental insulation support-member supporting the current-supplywires and the support-wires for said anode and grid, and a second insulation-support-member supporting the current-supply-wires for said electron emitting source.

2. An electron discharge device comprising an evacuated vessel, a stem, an electrode system consisting of a plate, a grid and an electron emitting source, current-supply-wires passed through said stem to said electrodes, support-wires for said electrodes, one glass rod supporting the currentsupply-wires and the support-wires for the anode and grid, and another glass rod supporting the current-supply-wires for said electron emitting source. v

3. An electron discharge device comprising an evacuated vessel, a stem, an electrode system consisting of a plate, a grid and an electron emitting source, current-supply-wires passed through said stem to'said electrodes, support-wires for said electrodes, a supplemental insulation-supportmember supporting the current-supply-wires and the support-wires for the anode and the grid, and a second insulation-support-1nember supporting the current-supply-in wires for said electron emitting source and additional supportwires connecting and stiffening said insulationand the grid, and another glass rod supporting the current-supply-wires for said electron emitting source and additional support-wires connecting and stiffening said glass rods oneagainst V the other.

5. An electron discharge device comprising an evacuated vessel, a stern, an electrode system consisting of a plate, a grid, a heating filament and an equipotential cathode insulated from this heating filament, current supply wires passed through said stem to said electrodes, supportwires for said electrodes, a supplemental insulation-suppcrt-member supporting the currentsupply-wires and the support-Wires for the anode and grid, a second insulation-support-member supporting the current-supply-wires for said heating filament and support-wires to support said first insulation-support-member, and a third insulation-support-mernber supporting one pair of support-wires for the equipotential-cathode and another pair of support-wires securedto said second insulation-support-member.

6. An electron discharge device comprising an evacuated vessel, a stem, an electrode system con sisting of a plate, a grid, a heatingfilament and an equipotential cathode insulated from this heating filament, current supply wires passed through said stem to said electrodes, supportwires for said electrodes, a supplemental insula- 1L5 tion-support-member supporting the currentsupply-wires and the support-wires for the anode and grid, a second insulation-support-member supporting the current-supply-wires for said heating filament, a third insulation-support member supporting the anode current-supplywire and additional-support-wires connecting and stiffening said insulation-support-members oneagainst the other.

7. An electron discharge device comprising an evacuated vessel, a stem, an electrode system consisting of a plate, a grid, a heating filament and an equipotential cathode insulated from this heating filament, current supply-wires passed through said stem to said electrodes, support- LAG an equipotential cathode insulated from this heating filament, current-supply-wires passed through said stem to said electrodes, supportwfres for said electrodes, one glass rod supporting the cUrrent-supply-Wires and the supportwires for the anode and grid, a second glass rod supporting the current-supply-wires for said heating filament, a third glass rod supporting the anode current supply Wire and additional150 9. An electron discharge device comprising an.

evacuated vessel, a stem having a press portion, grid plate and filament, an insulation-supportmember and a complemental-insulation-supportmember, one pair of filament-current-supplywires secured to said press and to said insulatingsupport-member supportingsaid insulation-support-member, means to secure said filament to the said pair of filament-current-supply-wires, one pair of support-wires secured to said insulation-support member and to said complementalinsulation-support-member and means to secure said support-Wire to one end of said grid,'to support said grid, one grid-voltage-supply-wire secured to said press and to said complemental-insulation-support-member and means to secure said grid-voltage-supply-wire to the other end of said grid to supportthis other end of the grid, one support-Wire secured to said complementalinsulation-support-member and means to secure said support-wire to one point of said plate to support the plate, and a plate-current-supply- Wire secured to said press and to said comple-' mental-insulation-support-member and means to secure said.plate-current-supply-wire to another point of said plate.

10. An electron discharge device comprising an evacuated vessel, a stem, having a press portion, grid, plate and filament, a glass rod and a second glass rod; one pair of filament-current-supplywires secured to said press and to said second glass rod supporting said first glass rod, means to secure said filament to the said pair of filamentcurrent-support-wires, one pair of support-wiressecured to said first glass rod and to said second glass rod and means to secure said support-wire to one end or" said grid, to support said grid, one grid-voltage-supply-wire secured to said press and to said second glass rod and means to secure said grid-voltage-supply-Wire to the other end of said grid to support this other end of the grid, one support-Wire secured to said second glass rod andrmeans to secure said'support-Wire to one point of said plate to support the plate, and a plate-current-supply-Wire secured to said press and to said second glass rod and means to secure said plate-current-supply wire to another point of said plate. V

- EDGAR ROMHILD.

Images