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Патент USA US2088493

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July 2"], 1937..‘
|_ éUTHERLlN ET AL
‘
2,088,493‘ -
Filed June 21, 1935
26 24 27
INVENTORS.
WITNESSES ;
,‘z
lee ébf/zerl/n one’
?berfJ/f ray/79f‘
BY
W
AT
NEY
V
iPllellted
__2,oss,49i
1937' " -
y*miss-sums PATENT _ oi-"Fics
4
_
cs'rnons BAY
>_
Lee suissiis.
’
.
|
| 1
.-
4
.
Albert 1. assoih.
_.
i
'
V
Pittsburghl’asaoorporation of?
Application June 21,. ms, 'sss'isi no. tissue
- 1o
(cum-21.5) .
Ourvinventio'n- pertains to cathode-ray_ tubes,v
and more particularly to tubes of the type suit
FIB-s5 lls-a similar‘ view .sliowingthebly _ .
turned ninety degrees;
serving or photographicail-y
the-wave
s shapes of varying ‘current 'or voltage quantities.
_
V
Fig. dis a top plan view of the assembly;
Fig; 'iis a detail vview showing the electron
able for‘oscillographic circuit analysis as bygob¢ ,
.source; and,
'
5' I'
Fig. 8 'isa detail vi'ew‘showing s section taken
axially through the electron gun which projects
‘
Cathode-ray tubes, in general; comprise means
_- for generating a-stream of electrons which is
' projected vas a small spot;upon a-"?uorescent
screen. By ‘passing ‘the stream of v electrons
_
10 through either an electrostaticineld, or ‘a mag
theelectronstream.
v.
.‘
Referring more speci?cally to Fig." 1' of the
drawing, our cathode-ray tubeic‘o'mprises a glass 10
netic?eld.
issw'erved'fromitsstraight" container i, which enclosesand supports ,the va
path and-traces a ‘pattern or wave onthe‘screen‘ rious elements. The vessel is preferably ,of an
which corresponds to the control voltage which’ inverted conical formationhaving a tubuhr por
' creates
tion extending from the apex theerof. The base
ileid.
"Numerous applications‘ of such- tubes have > to! the conical portion is preferably convex and 15
already beenmade'inyindustrial routine testing, the interior surface is provided with a fluorescent
but'the' tubes' previously available could not be _ screen 3 which may, for example. consist of a
uniformly assembled; did not have uniform char
_
coating of willemite, a crystalline substance con- '
been di?icult to ob- ' taining zinc, which becomes a vivid green‘ when
acteristics and.it'_-has
‘
struck by a stream ot'electrons. Inorder to drain 20'
oil the electrons, the screen is made slightly con
ducting and is in contact with the second or high
m tain a sumciently ‘sharp focus of. the trace on
the
.
.
- It is accordingly an object oi‘ our invention
4 to provide cathode-ray tubes having uniformly
improved
characteristics.
-
.
'
‘
-
"speed accelerating anodewhich comprises a sil
ver coating 4 provided on. the inner surfaces of
v
_A further object of our-invention is to pro the side walls of the conical portion. A terminal 25'
vide cathode-ray tubes wherein the component ‘5 extending from the, side of the conical portion
parts may be assembled and
with uniform aiiords convenient connection' to this high speed
Legumy to insure. improved iocusing’chsracter
cm
.
-
.
n
.
.
'
__
.
or. second anode. It is to, -be understood. how-'
>
'
ever,
that
the
principles
of‘
our invention
are
_ ‘0' .- It is‘also an object'oi'_~our invention to. pros‘.v also-applicable to cathode-ray tubes which ‘are 30
‘
vide a cathode-ray tube wherein the component _
as a rigid unit upon one- -
|
' Lelements
provided-with a_ second‘ anode.
'
I
.
'
e" lower end of the‘ tubular portion of the
"vessel is provided with “a contact plug 0 to es-.
A further object of‘°our invention is toapro ' 'tablish- electrical connection through a conven
' ,, vi‘de. means’ for.
of sharply de?ned» tional socket (not shown) to various circuits (not .35
" shown) from which the tube is to be energised.
.streamofelectrons.
The inventionitself,
both'as'to'its;
It isidesirable to keep the test and timing circuit "
'_ connections as far removed from the other cir
cuitsas possible, and for
reason the tube is
the'follow-V provided with hollow conduit portions v‘I proie'ct- ‘40
49 thereof, will hest'be understood
- in:
when ‘ ‘ling. radially from an intermediateportion' of the
1 tube for leading individual conductors into the- -
a speci?c
in conjunction wits-ms‘;
-
Therearefour suchradiallyettended
‘ arms, and eachiisclosed by-a terminal cap 8 to
iisia.
axis of'P-a
‘ 'v‘iswsslonsiths'iodsi-i which the timing and test circuits maybe'con
tube
gin,with,ourinvention;
v
_ nectediin any suitable manner. .
tigJissplanviewof-the'sochetplugonthe
_
from the owe; end of thetubular por-.
j tionJof-“the vessel is a stem or press. ll through
\‘ 'endofthetube;
!h..8isasectionalviewtahenonlineIII--III ' which-conductors are extended-from thecontacts 50.
in'the contact plug to- the ‘elements within the
‘Hindi:
_
a
v-
-‘
y-frlgiisan-enlargedsideelevationalviewof
the integral membly
5tube'.- All electronemitter II, described in de
ton hereafteL-is supported on a-p'in .ll_ which'lis >
the. elements. ’ \
ofthetubewhicheismountedasaunltonthe
into the press. A control electrode
_ll,,'which comprises an inverted-cup having-an
jopsmsg’intneiiottom moi-soil; is also mounted‘ 65
2.
A
_
2,088,498
44 provides direct ‘conductive connection between
> On pinsli supported in the\press and is positioned ‘
with the opening directly above the electron vthe cylindrical shield member 22 and its associ
source l2. By applying suitable potentials on this ated de?ecting plate 42, and prevents-the accumu
electrode the electron emission from the. source
I2 may be accurately controlled.
lation of electric charges. ‘ The other. three
bracket arms supporting and joining'the‘plates
The remainder of the tube elements are assem- .~ are provided with the glass insulating beads.
The insulating glass beads “adjacent the par- 7 '
bledi together into a unit which is supported by
three pins 2| welded or soldered to. a '?exible'
metallic bandv 22 which is'clamped around the
allel edges of the-plates 4i and 42 are quadruma
larged side elevatlonal view of theassembly from
the same position as Fig. 1, and Fig. 4 shows how
one of which 41, extends downwardly from each
bead to be secured to diametrically opposite
points on the cylindrical shield member 33, and 15
nous, having a formation somewhat similar to a
four leaf clover, for securing the ends of four 10
stem
TheIIunitary
by a bolt
assembly
or screw
is 23.
more clearly
- shown in metallic bracket members, two of which 46, ex
Figs. 4 and 5,-in which the latter shows‘ anen- ' tend laterally to be secured to the adjacent plates, .
the structure appears when turned ninety degrees‘
15
on its axis.
the fourth of which 48, extends upwardly from
-
each of the quadrumanous beads to be secured to
a second pair of de?ecting plates 5| and 52. It
Directly above the electron emitter l2 and con
' 'trol electrode i4 is‘ a cylindrical accelerating
anode 24 forqaccelerating the electrons discharged . will be apparent that the ‘arrangement of the
quadrumanous beads 45 serves not only to rigidly
20 from the electron emitter i2 and projecting them
25
as a sharply de?ned stream. This device com
support and insulate the plates, but also‘ to hold.
prises a closed cylindrical member having at least
them rigidly in proper spaced relation.
one partition wall or diaphragm 21 intermediate
its two end diaphragms 26 and 28, as'shown mor .
The second pair of de?ecting plates 5| and'52
comprise the uppermost elements of the assembly,
clearly in Fig. 8.
x
.
_ .
. and to hold them in rigidly spaced parallel rela
I
A small hole is provided in each diaphragm in
tion, a pair 01’ insulating bracket arms 53 are
provided, one of which is' connected across. each
oi- the. adjacent opposed edges. of the plates. To
series alignment ,whereby the emitted. electrons
pass through the three diaphragms in succession.
By charging this'cylindrical accelerating anode
hold the upper pair of plates ‘in rigidly aligned
relation above the first pair of plates, additional
30 with a suitable positive potential relative to the
electron emitter, the approaching electrons are
insulating bracket arms 54,‘
accelerated.‘ Some 01' the electrons ‘passing
the upper and the lower plates, in, offset relation
through the ?rst diaphragm 26 and impinging
e secured between
to the arms 48 projecting ‘upwardly ‘from- the
quadrumanous beads 45, thereby providing a four
point support and shading a bracing structure 3-1
upon the side walls and edges cause the emis
_ sion of secondary electrons, some of which pass
through the opening of the second diaphragm 21 to prevent lateral ?exing oi’ the latter.' A ?exible >
at a wide angle. The third diaphragm 28,. how conductor i‘l'is attached .to each one of the de
ever, almost completely eliminates the secondary ?eeting plates ,and is' adapted to be extended
electrons which have not passed through the holes through the corresponding lateral conduit pot-w
in both the ?rst and the second diaphragms.
' tions oi the vessel ‘for cbnnection to the terminal 40
By mounting a smaller cylindrical member 29
on the last diaphragm 28. any stray electrons.
caps when assembled. ‘i
emerging from the third ori?ce willbe collected. . .
'
v
>-
Y ,
serves a very important
function as a rigid struc
‘
_
>tural unit suitably spacing the de?ectingplates
If desired, a greater number or diaphragms~ than‘
three may be provided. ‘The electron gun “is
supported by the three external brackets 2|
welded or soldered to suitable?nsll on theouter
walls of the gun and extending down and-secured
to the ?exible band 22 which is clamped'on the"
stem ‘I I.
.
The cylindrical shield member “not only
away from the ?rst anode 24 without the necessir ~ 45'
ty of using long ?exible bracket arms‘, but it also
serves a very important function as‘an electro
static shield. In the operation of the cathode
ray tube, the electron emission causes electric
'
. charges to accumulate on the glass beads. ‘ Such
Directly above the electron gun 24, in axial ‘charges set up strong 'electrostatic.~?elds which
alignment therewith, acylindrical member II 8 de?ect theelectron- stream. 'i'rom' its straight
course it it is unshielded. The cylindrical mem
oi the same diameter is mounted in spaced, in
sulated relation. The cylinder serves the purpose ber "shields the beam in itspath between‘ the
oi'an" electrostatic shield and also as a structural . ?rstanode 24 and the ?rst‘ pair oi.’ plates 4i, andv
member rendering possible the rigid union of the . 42 and causes the tube to function properly. ’ a
various elements of the tube., It is rigidly sup- .The' union of the various elements Jo! the.
lfportedin' suitable spaced relation from the-elec ‘cathode-ray‘ tube into a rigid assembly'having;
tron-gun, by three externally disposed'bracket predetermined spacedrelation is a very important.
arms 24 extending upwardly .irom the electron‘, contribution to the successful operation oi’such
,
equally
around the circumfer 'a- device. This is true not only because oi’ the
60
- gun 24 and-‘spaced
ence. Eachbracket arm“ consists of two angu-'
'- lar metallic members ll having their adjacent
importance or maintaining the accurate, align- - >
ment or the various elements and the electron
ends sealed insglsss insulstorbead II and their 1 stream therethrough, but also'because or the fact
diverging ends secured to the cylinders, as clearly that where a series of diaphragms, cylinders or 65
shown by the' sectional view 0! one such insulat ;the like are used, through which an electron
ing bracket in 1118.14. >‘By’making the insulated . stream passes. such elements act similar to lenses ‘Y
bracket arms as short as possible, and providing in optics and must be properly adjusted with‘ re- .1
thematthreeormorepointssroundtheciroum
'
.70
-' spect to distance,.dimensions'and voltage in order
ierenceo! the cylinders, the latter are quite rigid
to give the best light and the sharpest de?nition’ 70
.
’
4|
42 are sup
post'edibovethecylindrical member I! in suit
pair'oide?ectingplates
bracket
M13211!“
members. oneoi
relation
is‘ able
onthescreen.‘
'1
~In one‘speci?c embodiment-oi our invention.
in'which the cylindrical elements had‘ a diameter
or '% or an inch, it-wasi'ound preferable to- use "
brschet
by tour members a small cylinder'on the anode having alengtlr and 7 -
i
5
adiame'tereqllnlto%ofan.inch.andtheanode
may be readily
'
?ystJe'cond andthirddiaphragmswere
‘Paced ?ll-?lly. The holes.054.
in .096
have shown and described certain
' ' ' '
oi our invention. wearetuily
aware that manymodi?cationsthereoi arepossible.
‘Our invention, therefore. is not to be'restricted 6
and .04_1 inch in diameter
The de
?ecting'plateswere%xlinehandtheplatesoi
. 5
3
. ewe
x.
except-insofar. as is‘ necessitated by the prior a
ieschsetwetrespaceds'sotaninch. Thecontrol
ahd'thescope'oi' the appended claims.
electrode comprised an inverted cup it'inch'in
diameter, 99 inch long. with admin .088 inch in
vWe claim as our invention:
'
.‘
_ I
l. vl'i unitary assembly for a cathode-ray tube
crating anode. sets of de?ect- 10.
ing plates, an ectrostatic shield about the elee»
‘ diameter and spaced’.030 inch from the anode.
comprising an
"li‘he cylindrical-shield, the anodeand the sets oi
'plateswerespacedaxiallyby iioianinchi The
between ‘said anode and plates and
dimensions and spacings above set forth are given
means for rigidly supporting saldiplates on said
anode comprising s’aid electrostatic shield and
satisfactory ior ‘a speci?c set of conditions and .insuisiors.
said electrostatic ‘shield disposed in 15
is not to be construed as imposing 1imitations,_ spaced relation
saidjnsulators to protect the
since the desirable features of our‘ invention are electron stream ‘to
from the deiléc?ni in?uence-oi
merely for an example oi’ a'structure which is
' - applicable to
'
all cathode-ray tubes
'
'
'
'
iargeaand
-
'
Y
-
_
_
I
‘.electrostdtic?elds
set
upby
accumulated'elec
ent ~and spacingwhen the.
Accurate
'trical charges on said insulators.
‘25A .unitaryi-ass'embly‘ior a cathode-raytube2o
are
and ‘sup? 'comprising
20 ‘?ectins p
a cylindrical accelerating anode, a
ported-on the. walls oi the glass‘ enclosin'e'is-very
axial alignment therewith,
di'?icult to obtain and is not permanent. _In the‘ cylindricai'shieldin securing
said cylinders in‘
cathode-ray tube constructed in accordance withv spaced insulated relation, a pair 0! spacedpar
curinventionythese elements
?rst properly allel de?ecting-plates, external means ior ‘securing 25
25 spaced and united on the press before it is in'-.
serted in-the'vesscl. instead of attempting to
properly align and space the elements as the
press is
‘ insert'edand sealed into the vessel: . The
said plates in insulated relation on said shield in
spaced relation- to the anode and the extended
‘tube is much more accurately obtained .inlthis
additional support and 'conductfte. connection
arrangement and
80
.
oi’ the elements 0!. the
axis thereo?a metallic member connected be
tween one of said plates and the shield to provide 80
therebetween. a second pair_'oi' spaced parallel
manner. and thetubeso'constructedissorugged. plates disposed at right mid- to the Plane of
that its characteristics are not
a?ect
said that plates.‘ and external means for
’
ed by moderate shocks and vibrations.
platesininsulated'spacedre
As-shown in Pig. '1,‘ the electron emitter may be saidsecondpairoi
oi'the electrically heated ‘type comprisin'ga heater 1 lation from said iirst plates andspaced' about the ‘3-5
ll pi?netungstenwiretoiledaboutthrou?ha
extended axis, of said anode.
-
:3. A cathode-.ray'tube\ , prising an electron
plurality of holes extending axially ini'spaced
emitter.
an accelerating anode‘ for ‘accelerating
through
a"cyiindri<=i.I-1
rod
if
of
parallel ‘relation
thereirom, sets
magnesium oxide enclosed within a metallic nickel and projecting an electron stream
_ tic shieldabout 4°
of de?ecting plates, an‘
1i’.
is'suitably
in?ll-bed.
The;
5loosen a from which
electron path between said anode and plates,
heater shell ‘I is closed at the upper end and-is - the
‘(or rigidly: supporting said sets oi plates on
provided with an'insulator 04 adjacent theinnei" means
said
‘anode
comprising -_said electrostatic shield
_suriace and with. a suitable electron emitting
said electrostatic shield beingiin 45
and insulators,
substance ‘I onthe upper suriace.
.relation to said insulatorsin protect
the l
ot-the‘stem ll iive conductors
_
electron stream'irom the de?ecting in?ueneeoi
extend to eorrespondingeontact prongs in the electrostatic
?elds set up 'by'electrlc charges on
I
.
s
control'plug 8; Two of the conductors ‘are con.
said insulators. an evacuated vessel, a stem there
nootedtotheheatertlintheelectronemittena
said anode on said
to the shell Ii. a fourth iii-coir-v .-in, and mea'n's'ior
. third is com:
60
I
electrodes“ the
con-'
nested
ductor is
toconnected to ‘the tint accelerating anode
stem.
'4. A cathodeeraytube
- -.
comprisingian
.
electron‘
.
.50.
"
sourceQ'a control electrode,v an. anode; de?ecting
p1ates._.means ior rigidly'securing said electron
plied tothe ?rst anode I4 to cause it to project - source, control electrode, anode. and plates to
_
in spaced insulated relation. an evacuated 55
I stream oi'electrons. A much higherpodtive gether
‘god's
vessel‘ for enclosing and supporting said elements.
is applied to the second anode compris . astem
extendinginto said vessel. means for sup
the'silvercoating on the‘ inner surface oi
said electrode source on said stem. hollow
the ‘conical portion oi the-vessel to 'acce'leratethe porting
arms projecting radially from-‘an intermediate
electron streamaiterithasbeende?ectedbythe portion
of said vessel adjacent said plates, a ter~
plates to thereby create a much brighter ‘spot
minal
cap
the end oi each arm. and-a ?exible
on the screen..as set iorth in Patent No. 1,810,018 conductor on
extending
from each plate through an
of D. E, vHowes. The electron stream is thus pro
_
irom the
anode at low velocity for adjacent armto the associated-terminal cap.
. 5; A cathode-ray tube comprising an electron 65
great sensitivity. or maximum de?ection by the source.
a'eontrol electrode. a cylindrical acceler
.24.
_
.
-
4
_
.
.
I
- In operation a suitable positive potential is‘ap-'
65 > plates, and it is'then accelerated to high speed
to
‘ating anode, a stem, means ior supporting said
produce
a7bright sharp trace on-the
.
node on saidstem. a cylindrical shield in
_In view ~oi thehlgh'positive potential. on the sec
ond anodeand the. proximity of the de?ecting‘ ?ignmenttherewith', external means ior securing
plates thereto! it is preiera'bleito' groimd the sec
i
.eiseints to be
any‘ suitable manner. since the‘ _
_
’
plates in-insulated rela
are not usually very'well' means for securingsaid
inspaced‘ relation to the anode
__ seen that weihave provided
anju?n'oved cathode-‘ray :tube and aamethod o!
tion on said‘ shield
' andthe‘extended'axis
‘thereof. a metallic member
connected between oneoi saidplatesandtheshield
to
and condi'iotive con.
-
4
mosaics
I
"
'-
-
-
'
I.
>_
> nectton ith'erebetween, a secondv pair ‘of spaced ‘speed accelerating anode, and ai_ terminal con
parallel plates disposed at right angles to the -
plane oi said'?r'st plates, external means for se
curing said second pair of plates in insulated
spaced relation from said ?rst plates andspaced
aboutthec extended axis of said anode, andan
_ evacuated vessel for enclosing and supporting said
elements.
_
1
_
.
i
ductively connected thereto.)
.
l
.
8. A cathode ray tube comprising a container
having a cathode, a control electrode, a ?rst an
,ode, de?ecting plates, another anode and an elec
trostatic shield surrounding the electron dis
charge path intermediate said iirst anode and
said de?ecting plates.‘
~
_
>
'
. 6. A cathod'e-raytu'be comprising an evacuated
9. A cathode rag tube comprising a container
10 vesse1,-a stem extending, thereinto, a unitary , having a cathode, a control electrode, de?ecting 10
structure ‘supported on said stem comprising an platm, an anode and a cylindrical member insu
electron emitter, a control electrode, an acceler- - lated from said anode intermediate said‘ control
ating anode and sets 01' de?ecting plates, arms electrode ‘and said de?ecting plates and a direct
projecting from a portion of said vessel adJacent connection from said cylindrical member to one
15 said plates and ?exible conductors extending from of said plates.‘
said plates through said arms.
.
'
».
~
7. In combination ‘in a cathode~ray tube an
electron emitter, a control electrode, a ?rst accel
crating anode for accelerating and projecting a
20 stream of electrons therefrom, sets of de?ecting _
plates, an evacuated vessel, a stem therein, means
for rigidly supporting and insulating said elec
tron emitter, control'electrode, accelerating anode
and plates as a rigid unit on ‘said steam, a ?uo-'
25 rescent screen on the opposite end of said vessel,
10. A cathode'ray tube comprising a” container
‘having a cathode, a control electrode, a separate
of the electrons issuing. from said cathode, a
cylindrical conductingmember surrounding the
electron path, an anode, de?ecting plates inter
mediate said cylindrical conducting member and
said anode and a direct connection between one
01 said plates and said cylindrical member.
a conductive surface on the walls, of said vessel
LEE SU'I'HERIM;
adjacent tosaid screen comprising "a second high
.
__
-,
'
-_ AIL-BERT. .7. HARCHER.
DIQQL'AIMSR
..
I
mesa-493.4» sumac, Y‘Wilkinsburg, and‘ Azu?J. Harchcr, Homestead, Pa.
Oa'r'nonn R'Ar "Tuna. Patent ‘dated ‘July 27, 1937-. Disclaimer ‘?led
v _ November 15', 1939.,fby theasaignee, Westinghouse
Company.‘ .,
S
enters " '
- \
claims
Gama Btu-nib" 5, 1939.1
_ -
structure adjacent thereto restricting the path
the patent_.'
d: Manufacturing
20
4
mosaics
I
"
'-
-
-
'
I.
>_
> nectton ith'erebetween, a secondv pair ‘of spaced ‘speed accelerating anode, and ai_ terminal con
parallel plates disposed at right angles to the -
plane oi said'?r'st plates, external means for se
curing said second pair of plates in insulated
spaced relation from said ?rst plates andspaced
aboutthec extended axis of said anode, andan
_ evacuated vessel for enclosing and supporting said
elements.
_
1
_
.
i
ductively connected thereto.)
.
l
.
8. A cathode ray tube comprising a container
having a cathode, a control electrode, a ?rst an
,ode, de?ecting plates, another anode and an elec
trostatic shield surrounding the electron dis
charge path intermediate said iirst anode and
said de?ecting plates.‘
~
_
>
'
. 6. A cathod'e-raytu'be comprising an evacuated
9. A cathode rag tube comprising a container
10 vesse1,-a stem extending, thereinto, a unitary , having a cathode, a control electrode, de?ecting 10
structure ‘supported on said stem comprising an platm, an anode and a cylindrical member insu
electron emitter, a control electrode, an acceler- - lated from said anode intermediate said‘ control
ating anode and sets 01' de?ecting plates, arms electrode ‘and said de?ecting plates and a direct
projecting from a portion of said vessel adJacent connection from said cylindrical member to one
15 said plates and ?exible conductors extending from of said plates.‘
said plates through said arms.
.
'
».
~
7. In combination ‘in a cathode~ray tube an
electron emitter, a control electrode, a ?rst accel
crating anode for accelerating and projecting a
20 stream of electrons therefrom, sets of de?ecting _
plates, an evacuated vessel, a stem therein, means
for rigidly supporting and insulating said elec
tron emitter, control'electrode, accelerating anode
and plates as a rigid unit on ‘said steam, a ?uo-'
25 rescent screen on the opposite end of said vessel,
10. A cathode'ray tube comprising a” container
‘having a cathode, a control electrode, a separate
of the electrons issuing. from said cathode, a
cylindrical conductingmember surrounding the
electron path, an anode, de?ecting plates inter
mediate said cylindrical conducting member and
said anode and a direct connection between one
01 said plates and said cylindrical member.
a conductive surface on the walls, of said vessel
LEE SU'I'HERIM;
adjacent tosaid screen comprising "a second high
.
__
-,
'
-_ AIL-BERT. .7. HARCHER.
DIQQL'AIMSR
..
I
mesa-493.4» sumac, Y‘Wilkinsburg, and‘ Azu?J. Harchcr, Homestead, Pa.
Oa'r'nonn R'Ar "Tuna. Patent ‘dated ‘July 27, 1937-. Disclaimer ‘?led
v _ November 15', 1939.,fby theasaignee, Westinghouse
Company.‘ .,
S
enters " '
- \
claims
Gama Btu-nib" 5, 1939.1
_ -
structure adjacent thereto restricting the path
the patent_.'
d: Manufacturing
20
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