US2392969A

US2392969A - Photoelectric tube

Info

Publication number: US2392969A
Application number: US329953A
Authority: US
Inventors: Everett H Bickley
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-04-16
Filing date: 1940-04-16
Publication date: 1946-01-15
Anticipated expiration: 1963-01-15

Description

E. H. BICKLEY PHOTOELECTRIC TUBE Jan. 15, 1946.4

Filed April 16, 1940 2 Sheets-Sheet l Jan. 15, 1946.

E. H. BICKLEY PHOTOELECTRIC TUBE Filed. April 16, 1940 2 Sheets-Sheet 2 Patented Jan. 15, 1946 UNITED STATES PATENT ori-ics v PHOTOELECTRIC TUBE Everett H. Bickley, Bala Cynwyd, Pa. Application April 16, 1940, Serial No. 329,953

(Cl. Z50-165) 18 Claims.

Thepresent invention relates to radiation sensitive devices, and more particularly to those known as photoelectric tubes,

Generally, I aim to provide such a device as will be simplified -in construction, of more permanent characteristics and longer life, and especially adaptable for relatively inexpensive, safe and uniform manufacture by quantity production methods.

A prime object is to provide a novel method and means whereby application of the cathodic light sensitive means at a location for engagement by a coacting contactor is assured.

It is also an object to provide the light sensitive means on the interior of the envelope of the tube by vaporization and condensation of a cartridge, andA more specifically through the rise of temperature necessary for but prior to the vaporization of the cartridge to temporarily space the contacter therefrom so that the light sensitive means will be deposited on the envelope at the zone of contacter engagement when the vaporisation occurs.

Another important object is to provide for establishing conductivity between cathodic light sensitive means and contactor selectively at a plurality of zones or locations, which especially enables expeditious correction of an inoperative, partially impaired or faulty condition attributable to faulty deposition, displacement or wear of the light sensitive means.

I further aim to provide a tube especially having great stability, speed and high response to the radiations in the spectral region commonly called blue and of shorter wave length.

I also aim to provide a novel form and composition of vaporizable cartridge used in the formation of the light sensitive electrode coating within the envelope or tube.

Various additional objects and advantages will become apparent from a consideration of the description following, taken in connection with vthe accompanying drawings, illustrating operative exemplary embodiments.

In said drawings:

Figure 1 is a central longitudinal sectional view through a photoelectric tube constructed in accordance with the invention;

Figure 2 is a cross sectional view taken on the plane of line 2-2 of Figure 1;

Figure 3 is a central longitudinal sectional view through the photoelectric tube of Figure 1 in the course of manufacture thereof, taken at right angles to Figure 1;

Figure 4 is a cross sectional view taken on the Figure 9 is a longitudinal sectional view through another modiiied form of photoelectric tube; and. Figure l0 is a longitudinal sectional view through a further modied form of photoelectric tube.

Referring specifically to the drawings, and rst, to the form of Figures 1 to 5, I0 designates a suitably shaped bulbous evacuated envelope adapted to be mounted on a conventional base, or other--V wise, as usual in the art. Said envelope may be of lime glass, fused quartz, or other non-conducting material which is not chemically detrimental to the materials or parts it encloses.

Said envelope has an inturned press Il at one end thereof containing spaced apart short conductor wires l2 and I3 which are sealed in and by the glass when the latter is blown to provide the press and to the outer ends of which wires l2 and I3, exterior conductor leads i4 are welded. At the time the envelope with the press Il` is blown, an integral glass tube i5 (Figure 3) is attched through which the envelope is later evacua ed.

Welded to the inner end of said wire l2 is an electron collecting electrode i6 which is relatively.

rigid and unbendable by heat. A contacter Il is thermostatic so as to be bendable by heat to move both inwardly and sidewise away from its normal operative position engaging the inner wall of the envelope, as shown in full lines in Figures l and 3, toward electrode I6 to the dotted line positions in the same gures. Usually, contactor l'l is bimetallic and is welded to a connectingconductor |B, which, in turn, is welded to the.

inner end of the adjacent conductor wire i3. For the electrode i6 and connector i6, I preferably employ a metal having Ya thermal coecient of expansion relatively high with respect to that of the material of press Il, so that on cooling, the metal will shrink away from the glass of the press leaving a space between such glass and the electrode I6 and conductor I8.

When the electrode iis secured in place, it carries a cartridge I9 welded or otherwise secured thereto at connection 20, andalso carries a small nickel, steel, tantalum or other metallic washer or disk 2l welded to the electrode I6 and normally spaced'about d: of an inch fromthe pl'eSS.

Said cartridge I9 generally corresponds to and4 23 during the marginal welding Vthereof togetherV at 24. The pellet 26 is preferably composed of 1.26 parts of dehydrated potassium chromate and 1.00 part of a fine metallic powder prepared from barium and aluminum alloy combined in the proportion of 1 part barium-'toV 1 part aluminum, all parts mentioned and to bermentioned beine` by weight. If desired, from approximately 0.15 part to approximately 0.25 part, by weight, of finely powdered magnesium may be `added. Where the pellet is too soft, aluminum powder can be used as a binder. I may substitute as the ne metallic powder, with 1.26 parts of highly compressed potassium chromate, 1 part of powdered magnesium and aluminum, combined in the proportion of 1 part magnesium to 1 part of aluminum. The proportions may be varied since pellets have been produced having 5 parts of potassium bichromate or potassium .chromate down to 1/2 part of either potassium blchromate or` potassium chromate to l' part of the fine metallic powder. The potassium chromate is preferred over potassium bichromate because less gas is evolved and the pellets can be made smaller, since a large quantity of the potassium bichromate hasrto be used in proportion to the metallic powder to obtain the same yield of potassium.

The envelope I6 is usually transparent and provided at any desired location with a window Ia for the reception of the desired radiations by the tube. v 1 f The parts are all assembled as described before the envelope I0 is evacuated and before vaporization of the pellet 26 in cartridge I9, the tube at such stage being as shown in Figures 3 and 4. The gases'and vapors are evacuated from the envelope IIJ in any known manner through the tube I5, following which the tube is thoroughlyY baked at high temperature and the metal .parts are heated by electro-induction Vor other means until all absorbed and adsorbed gases and vapors are driven o. Thereafter, the cartridge I9 is subjected to additional heating of a higher degree, sufllcient to decompose the pellet and release the vapors therefrom through ports26' which vapors condense on and adhere to the inner surface of the envelope which is relatively cool to form the light sensitive cathode nlm 21. After additional evacuation to a high point, the tube I is sealed oil with a torch.V Before sealing off, asmall amount of inert gas such as argon mayV bea-introduced or hydrogen sensitization may be used according to known methods. Electrode I6 constitutes an anode coacting with the cathode 21, and they are insulated from each other 'by the glass of the envelope at the press.

Attention is particularly called to the fact that upon subjecting the device to heat-the contactor I1 will be heated and will move inwardly and.

sidewise from the fullline position shown in Figure 1 to the dotted line position in the same ligure, thereby exposing that portion or zone of the inner surface of the envelope I0 which it normally engages, and, hence, during vaporization, the vapor from the cartridge will enter such zone andrdeposit and condense thereat, the contactor I1 upon cooling automatically moving to its original or normal position and engaging the film 21 at such zone. It is also to be noted that whenV the cartridge I9 is heated, the disk 2| also becomes heated, and during the vaporization of the pellet 26, the disk 2I prevents condensation of conductive material thereunder. 1n a vacuum, vapors move in straight lines from their source until condensed. They are reiiected from any heated object and for that reason the contactor I1 is moved sidewise and away so that no shadow will be formed on the envelope where it normally rests when at room temperature. Should the vapor condense on the press and short circuit the elements I6 and I8, when the tube is in use, induced radio frequency eddyv currents may be used to heat the washer'ZI, thus driving away the condensation and eliminating leakage.

Various changes may be resorted Ato provided they fall within vthe spirit vand scope of the invention. For instance, `I may use the modified form of Figure 6. This form corresponds to that just described, except as follows: The contactor I1 corresponds to that at I1 and like the former, is'thermostatic, being of one kind of Vmetal or bimetallic, as preferred. Surrounding the contactor I1( at the neckor collar 28 (Figures "l and 8) is a metallic contact 29. This contact 29 may be ofany suitable shape and, forin-l stance, capable of .beingmanufactured byqstamping. As shown,1it `is triangular in form.

As the photoelectric tube of yFigure 6 is manu; factured, the distal end portion of the contacter I1' isvin engagement with the electrode 21,- as in Figure 1, and thecontact 29 is out of engagement with such electrode 21, being in a retracted position, shown by dotted linesin Figure 6. l

Should engagement or contact between -the electrode 21 and contacter 11' be faulty at the time oi'manufacture orl become faulty in use from wearV or forV various reasons, effective contact may be reestablished by disposing the photo. electric tube of Figure 6 in an Yinverted positionl whereby the contact 29 is uppermost, thereupon subjecting the photoelectric tube to a jolt Awhich causes the contact 29 to slide fromthedotted line position of Figure 6 to the full line Vpositio'nof the same figure. Attentionis called to the tact that the contact 29 is so proportioned that a part thereofV wedges; between electrode ,-2-1V and; the

contactor VI1 so'thatthe latter Vis under tensign when the contact 29 is in the position of Figlllfei and, hence, leiective engagement of -the Ylatter with the electrode ,21 is maintained. Also note that, as best shown in Figure 7,' the contact-,2,9 at a plurality of yspaced locations-30, is in en-v gagement with electrode 2 1 to insure effective engagement. This contact 29 isrheld inthe Vfull line position of Figure 6 by the frictional tension of contacter I1', in addition to cohesionbef. tween the contact 29 and electrode 21.

The distal end of the contacter I1' maybe curled or otherwise enlarged at 3| to prevent dis engagement of thecontact 29 therefrom Since the contact29 engageslelectrode 21 at spaced locations, which are'on opposite. sides-,of and out of the zone of engagementof contacter. II` with electrode 21 l15h12 photoelectrictube may be manufactured .with the contactor .11 `Without thermostatic .properties :because after deposition ofthe electrode 2l, 'the contact 29 couldbe lolted from the ,dotted -line position of Figure 6 to `.the

full-line iposition thereof, and retained in place through the frietional tension `of the contacter I1 and engaged at the two locations 30 with electrodell.

The form of Figure 9 corresponds :to that-of Figure .6, with the exception of the contactor shown at Il", which corresponds .to those shown at ITI .and i1. This contactor I1," maybe made of one kind of metal or bimetallic, as preferred, but usually has afmetal wire of a single kind of metal and .normally ,of arcuate :.shape, `as shown. The contact 29 is also employed, .being mounted on Vthe contactor 1H" to function 'in lthes'ame marmer as in Figure 6.

i The contact 29 `is of a metal which may be attracted by a horseshoe magnet and, hence, by moving the magnet along the outside of .the envelope, the contact 29 may be moved from `the dotted line position in Figure 6 to the full line position shown in Figures 6 and 9, the horseshoe magnet being fragmentarily suggestedin the latter figure.

In Figure 10, a mica, metallic orother extension .33 is attached `to an `electrode i6 .corresponding to that at i6, and a contactar Ila is employed in lieu of those .at Il, Il' and l1". This contacter Ila is resilient, being a wire, of .a single kind of metal or bimetallic, as preferred. This contacter Ila has an angular extension 34 provided with a hook at 35 adapted for detachable engagement with the distal end of extension 33, as shown in dotted lines in Figure 10, whereby the contactor lla throughout is spaced from the electrode 21. The contactor I la is in such dotted line position when assembled in the photoelectric tube and the latter is evacuated and the cartridge I9 vaporized, Following deposit of electrode 21 through such vaporization, the photoelectric tube may be inverted, causing the contact 29 to slide into the solid position shown and then the tube is jarred or jolted to eiiect the disengagement from hook 35 through extension 33, so that the resilience of contacter Ila or the contact 29 Will engage the electrode 21.

Attention is called to the fact that the terms contactor and contactor means as used in the claims are of a breadth to include not only an element like Il, Il', Il" or Ila, but also an element Il, l1', I1" or lla, or any equivalent,

plus the element or contact 29, or any equivalent,v

as a part thereof.

I claim as my invention:

l. A photoelectric tube having an envelope, contactable light-sensitive means therein, an electrode to coact with said means, a contactor means, said electrode and contactor means being mounted and sealed within said envelope, said contactor means being normally in engagement with said light-sensitive means and movable by inertia into and out of engagement with said light-sensitive means.

2. A photoelectric tube comprising an envelope having an electrode and a contactor therein, a photo-electric surface within said envelope normally engaged by said contactor, vaporizable means Within the envelope to provide a lightsensitive deposit on said surface to coact with said electrode, said contacter being movable by heat of a degree insuilicient to vaporize said means to expose said surface before vaporizing said means to enable deposition at the zone of engagement face.

i :3. A iphotoelectric itube having an=envelope,1a light-*sensitive :electrode `means therein, an electrode tocoact Withsaid electrode means, acontactor engageable with said electrode means, and a .contact :carried by :the .contacter and movable along .the same toengage said .electrode means.

4. '1A `.photoelectric tube according to claim 3 wherein. said contact :is `sized and proportioned to .wedge at .a part `.thereof .between the electrode means and :said fcontactor to :tension the latter to :maintain the `contact -in `the wedged position.

:5. A -photoelectric tube having anenvelope, a photoeelectric Vcathode therein, an electrode therein coacting with said cathode, a conducting support'iwithinithe .envelpa Tand a conductive contact variable as to position relative `to the support :and .cathode held against lsaid cathode by:said:support.

6. A. photoelectric .tube having van envelope, la light-sensitive cathode therein, electrode `means andacoutactor extending into the envelope,.said contacter `being tensioned :to normally engage saidcathode, and Aa separable connection between .the vcontactor and electrode means to hold the contactor-out .of contact with the envelope at the zone of normal engagement, said connection being :separable-.through jolting `of the envelope.

7. .A material to be vaporized within envelope of a photoelectric .tube vto'provide .a cathode, 'the `n iateri'al comprising .by weight, 1.23 parts of :potassium chromate and `-1.00 part of a ilne metallic powder of a barium and aluminum alloy combined in the proportion of 1 part barium and 1 part aluminum.

8. A material to be vaporized within an envelope of a photoelectric tube to provide a cathode, the material comprising by weight, 1/2 to 5 parts of either of the group of potassium chromate or potassium bichromate. and 1 part of iine metallic powder of barium and aluminum mixed together.

9. A material to be vaporized within an envelope of a photoelectric tube to provide a cathode, the material comprising by weight, 1.26 parts of potassium chromate and 1.00 part of a fine metallic powder of a barium and aluminum alloy and combined in the proportion of 1 part barium and 1 part aluminum and from approximately 0.15 to 0.25 part of magnesium.

10. A material to be vaporized within an envelope of a photoelectric tube to provide a. cathode, the material comprising by Weight, 1.26 parts of potassium chromate and 1.00 part of a ne metallic powder of a. barium and aluminum alloy combined in the proportion of 1 part barium and 1 part aluminum and aluminum powder as a binder.

1l. A photoelectric tube having an envelope with a photo-sensitive cathode coating therein, an anode adjacent thereto, a movable contactor means, said anode and contactor means being mounted within said envelope, said contactor means being normally in engagement with said coating and movable into engagement with said coating at a plurality of zones of the latter.

12. A photoelectric tube having an envelope, a cathode therein, a conducting support within the envelope, a contact positioned by the support in engagement with the cathode, said contact being movable relative to the support through joltlng of the latter to different points of engagement with the cathode.

13. A material to be vaporized within the en of zthe electrode `with :the said fsur` Y process comprising heating said contactorto displacethe contacting portion thereof from.- said envelope, andV coating therinner surface of said envelope with a photo-sensitive material torform Va; photofsensitive cathode including the area..nor.

mally engagedby saidpcontactor. i, t u A n .15; The process of manufacturing a photoelec.- tric tube having ancenvelope enclosing an anode, there being-lead-in means for afphoto-sensitive electrode comprising a bimetalliccontactor, said process comprising heating said contactor to displace the 4contacting portion .thereof fromA said envelope, and coating the inner surface. of said envelope through subjection of the photo-sensitivematerial to heat of a temperature higher than during `the aforesaid heating to forni a photo-sensitive cathode including the area normally engaged by said contactor. Y

16. The process of manufacturing a photoelectric tube having an envelope enclosing an anode, there beingl leadfin means for a photo-sensitive electrode comprising a bimetallic contactor and a contactmovably mounted thereon, said .process aanmaacomprising heating said contacto'r to displace the contacting portion thereof from said envelope, and Ycoating the inner surface of said envelope with a photofsensitivematerial to form a photo-` tric tubehaving an envelope enclosing an anode,Y

there A'being lead-in means for a photo-sensitive electrode comprising a bimetallic contactor and a.

contact moi/ably vmounted thereon, said process comprisingheating said contactor to displace the contacting -portion thereof from said envelope,

and coatingv the inner surface of said envelope with a photo-sensitive material to form a photosensitive vcathode including Ythe areav normally engaged by said contactor, and magnetically moving said contacton the contactor to position, the contact relatively to the photo-sensitive cathode. A

V18. A capsule for vaporizationto provdea cathode vapor comprising initially separate disks having opposed depressions, a vaporizable compressed pellet Within and of a size filling and intimately iitting the depressions to cause registry of the disks in manufacturing the capsule, the walls of the depressions having dischargeports, and means marginally securing the disks together against rupture during discharge through the said ports. t Y

EVERETT H. BICKLEY.