US2743393A

US2743393A - Resistance adapter for thoriated filament valves

Info

Publication number: US2743393A
Application number: US431652A
Authority: US
Inventors: Zed J Atlee; Archie C Hallock
Original assignee: Dunlee Corp
Current assignee: Dunlee Corp
Priority date: 1954-05-24
Filing date: 1954-05-24
Publication date: 1956-04-24
Anticipated expiration: 1973-04-24

Description

April 1956 2. J. ATLEE ET AL RESISTANCE ADAPTER FOR THORIATED FILAMENT VALVES Filed May 24, 1954 2 Sheets5heet 1 INVENTOR; ZED J. ATLEE BY ARCHIE C. HALLOCK FIG! ATTORNEYS p i 1956 z. J. ATLEE ET AL RESISTANCE ADAPTER FOR THORIATED FILAMENT VALVES Filed May 24, 1954 2 Sheets-Sheet 2 FIG.4

INVENTOR. ED J. AT LEE FIG.6

Z BY ARCHIE C.HALLQCK ATTORNEYS thermionic valve. such as. u

Unitedv States Patent RESISTANCE ADAPTER ronrnonmrnn FILAMENT VALVES Z A e r hi go, nd-A h .,C:-.Hal 0 Elmhurst,

111,, assignorsto Dunlee Corp., Chicago, Ill a, corporation of Illinois ApplicationMay 24, 1954; Serial-N'o. 431,652 4 Claims. (Cl; 3151-58) The; present inventionrelatesto thermioniedeyices and more particularly to an. irnproved construction of r a ds n e po e up ircuit of. anX-ray, tube.

A majority of the rectified X-ray equipment. in usetoday utilizesa four-valve, full-wave type bridge rectifying circuit. Heretofore. th'erectifier. tubes. or valves have been. equ p ed. With puress cu- -fi amen Re cently there. have been. developedrectifier valves. utiliznsf hp a e ng n- Wi efil men w i h, p s s umerousdv tas s o r alve ti z na a Pu tungsten filament. Accordingly, it is highly, desirable that, as the tungsten, filament valvesneed. to. be. replaced; they be e la d with. l n 2 h? h i tedfi eut type o ever, the pure tungsten ,t'ype filament isa rdi'narily operated tr h m l. ol a e a -a. hor ated h st type filament and, consequently. thethoriated tungsten valve cannotbe substituted for apure tungsten typ e valve without changing the settings of.the circuit or otherwise compensating for the dilferences. in. operating voltage. Itis difiicult to effecta change inthe settingsof the circuit individual adjustments to.the rectifier tubes, butjinstead us a p ys a mm n adju m nt. r ..j t fier tubes- A eqrdi s y. q s n ject qt haa s n nv t n o installedfin a.circuit-.ar range d for use with va-lves off'the Pu n n pere a w a y, t an .ohiect f. he present nvensjten filament' ae. ec e al e where e. alve. an. be eadil adaateid ors e. i he 1 4 ircu des sn d c hor 'ated ten. filam n y e val es. r r: a e of. erujr'e tungsten filament type.

A fi j c b i e ven ion. s, q'nrevi e; 1. 1 ria dtung en filament type lve hav nsrme ns, or ea y .Qnue t sco t n -a esisto n er e with t filament of, the valve to; adapt the valve for the circuit inwhich it is to be used.

Another object of .theinventionais tgprovide means for readily connecting aneleqricaldeyicefsuch' as a resistor into the circuit of an electrical element of a thermionic device.

Other objects. and advantages Oftthfi :invention will be come. more apparenthereinaftera .'In acco rdance. withthe. illustrated;embodimentof the invention a-thoriated tungsten filament type valve iSPl'O- vided with a tubular mounting base on one end and upon which base is mounted a pair of terminal lugs, one of which is connected to the filament of the tube and the other to a terminal member for connecting the tube into the bridge circuit of an X-ray tube rectifier. The base is adapted to have a wire resistor wrapped therearound with the opposite ends of the wire connected to the lugs thus to connect the resistor in series with the filament. Alternatively, the resistor wire may be removed and the inasmuch as theusual circuitry, makesno provisionfor .p royide" a new, andimproved thoriatedgtung sten filament yre. valve h i m ans here v. hav ve an iee di two lugs interconnected to connect the filament directly to the terminal. Thus the valvemay be readily-adapted ice tocompensate the same for the circuit in which it is to be used.

For a more detailed description of the invention, reference is made to the accompanying drawings wherein:

Fig. l is a side elevation of a tube constructed. inaccordance with the invention;

Fig. 2 is a fragmentary view of the tube with the resistor wires unwrapped fromthe tube base;

Fig. 3 is a view similar to Fig. l with: the resistor removed and the two lugs interconnected to connectthe filamentdirectly to the terminal;

Fig. 4. is an exploded, fragmentary view. of the base member;

Fig. 5 is a sectional view taken along line 5-5 of Fig. 1; and I Fig. 6 .is a sectional view taken along. line 6-6 of Fig. 4. i I

.The rectifier valve or tube 10 shown in the drawing comprises a sealed envelope 11 of suitable material such as glass,,in which is. mounted a tubular anode 12 and cooperating cathode unit 13.. The envelope is shown as tubular in form and having reentrant necks 14,'at. the opposite ends upon which the cathode and anode aresupported inthe conventionalmanner.

. 'lihecathode, as shown, comprises a helical support member 17 formed of relatively heavy conductive wire and an emissiveportion comprising a long coil of thin, thoriated tungsten wire 18. The filament is connected to leads 19, 20 leading out through the pinch stcmZl at the cathode end of the tube,

'ter-minaL'member 29. which includes a metallic threaded portion '30 and a contact button 31 electrically insulated from the threaded portion 30" by an annular'ring 32 of suitable electrical insulating material. As illustrated, the filament lead 20'is'connecteddirectly to the contact'buttoo 31. The, other filament 'iead'w is adapted to be connected to thethreaded contact portion 30 through the means now to be described;

[The sleeve 25 is formed witha circumferential groove 35fin=its periphery. Mounted adjacent one edge of the gr0ove-35 area pair of contact means such asconventional'terminal lugs 36, 37, each of which includes a lead receiving socket 'or collar and'a leaf-portion. The sleeve 25 is provided with radi'allyspaced apart openings 4%, '41-'-in which the lug collars of the lugs 36', 37, respecttively, are loosely-received. The filament lead 19 is con- "nected to the collar of the lug 36; while the other-lug -37 'is connected-from its collar portion-hiya lead 42 to the threaded'por'tion 30"of the terminal '29 as illustratedin Fig. 6'." i

Theleaf portions of-each of the lugssd, 37 lie-juxtaposed the outer surface of the sleeve 25 and are provided with openings through which fastening screws 45, 46, respectively, may extend, the screws being threaded in suitable apertures provided in the sleeve. The leaf portions are of such size and the

openings

40, 41 are so spaced that one of the terminal lugs, the lug 37 in the instance shown, can be swung from the spaced apart position such as shown in Fig. 1, to an overlapping posi- 3 tion such as shown in Fig. 3 with relation to the other terminal lug 36.

Referring to Fig. l, with the terminal lugs spaced apart a resistance wire 50 may be connected at its opposite ends to each of the lugs by the screws 4-5, 46 and wound in loop fashion in the groove 35 as indicated in Fig. 2. The end of the resistor loop may be secured in place by a screw 51, as most clearly shown in Fig. 4-. It will be noted that doubling the resistor wire and winding it in a loop as shown is advantageous in that any desired length of wire may be easily mounted on the tube base by selecting the position of the screw 51.

In the event that it is desired to operate the tube without the resistor wire in its place, the

screws

45, 46 and 51 may be unthreaded and the resistor wire 50 removed and the lug 37 thereafter swung to place the leaf portions of both lugs in juxtaposition over the opening for receiving the screw 45, whereafter the screw may be put back into place as shown in Fig. 3, effecting a direct electrical connection between the

lugs

36, 37.

By reason of the construction provided, the valve tube may be easily and quickly adapted for use either in a circuit having settings for the pure tungsten type filaments or for circuits having settings for a thoriated type filament.

While the invention has been described in its relation to use with rectifier valves for X-ray equipment, it will be apparent that the invention may be utilized in connection with thermionic devices in general.

Having illustrated and described a preferred embodiment of the invention, it should be apparent to those skilled in the art that the invention permits of modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the appended claims.

We claim:

1. A thermionic device comprising an envelope, a filament in said envelope, a base member of electrical insulating material on said envelope and supporting a pair of terminals adapted to be connected to a source of electrical energy, and circuit means connecting said filament to said terminals including a pair of lug means mounted on said base member in electrically insulated relation and a resistor element removably connected between said lug means in series relation to said filament, at least one of said lug means being movable into contact with the other of said lug means to permit direct connection of said filament to said terminals upon disconnection of said resistor element from said lug means.

2. A thermionic device comprising an envelope, a filament in said envelope, a lead for said filament extending outwardly of one end of said envelope, a base member for said device including a sleeve of electrical insulating material mounted on said envelope end and terminal means for connection of the device to a source of electrical energy, a first terminal lug including a leaf portion juxtaposed the outer surface of said sleeve and a lead receiving socket means cooperatively received within an opening extending through the wall of said sleeve, screw means cooperatively received in said sleeve engaging said leaf portion for securing the same to said sleeve, a second terminal lug including a leaf portion juxtaposed the outer surface of said sleeve and a lead receiving socket means cooperatively received within a second opening extending through the wall of said sleeve, said second terminal lug being swingable about the axis of said second opening, said second opening being spaced from said aforementioned screw means by such distance that said second terminal lug leaf portion can be swung into electrical contacting engagement with said first terminal lug leaf portion, said aforementioned screw means being adapted to engage said second terminal lug leaf portion to secure the same in contact with said first terminal lug, said second terminal lug being swingable to a second position in noncontacting relation to said first terminal lug, second screw means cooperatively received in said sleeve for securing said second terminal lug in said second position, one of said filament leads being connected to one of said terminal means, a third lead connecting another of said terminal means to one of said terminal lugs, the other of said filament leads being connected to the other of said terminal lugs, whereby said filament is connected relatively directly to said terminal means when said second terminal lug is in said electrical contacting engagement with said first terminal lug, said first and second screw means being adapted to secure the opposite ends of a resistor element to the respective terminal lugs when said second terminal lug is in the second position thereof whereby to connect said resistor element in series with said filament.

3. A thermionic device comprising an envelope, a filament in said envelope, a base member of electrical insulating material on said envelope and supporting a pair of terminals adapted to be connected to a source of electrical energy, and circuit means connecting said filament to said terminals including a pair of contact means mounted on said base member in electrically insulated relation and a resistor element connected between said contact means in series relation to said filament, at least one of said contact means being movable into contact with the other of said contact means to permit direct connection of said filament to said terminals.

4. A thermionic device comprising an envelope, :1 filament in said envelope, a base member including a sleeve of insulating material secured to one end of said envelope, a pair of terminal means on said base member for connecting said device to a source of electrical energy, a pair of contact means mounted on said base in electrically insulated relation, at least one of said contact means being movable into and out of contact with the other, circuit means connecting one side of said filament to one of said contact means, circuit means connecting the other of said contact means to one of said terminal means, circuit means connecting the other end of said filament to the other of said terminal means, and a resistor element comprising an elongate wire wound about the periphery of said sleeve, one end of said wire being electrically connected to one of said contact means and the other end of said wire being electrically connected to the other of said contact means, whereby when said contact means are out of contact, with one another said resistor wire is connected in series with said filament and when said movable contact means is moved into contact with the other contact means said filament will be electrically connected directly to said terminal means.

References Cited in the file of this patent UNITED STATES PATENTS 242,897 Edison June 14, 1881 1,075,365 McNeel Oct. 14, 1913 1,526,353 Livingston Feb. 17, 1925 1,585,878 Rugh May 25, 1926 1,595,535 Wood Aug. 10, 1926