close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2118887

код для вставки
May 31, 1938.
T, JURRlAANSE ’
MERCURY CATHODE TUBE
Filed Feb. l5, 1937
di
.
2,118,887
Parenteel May 31, 1938
2,118,887 >
UNITED STATÉS EBATÈN’Í GFFICE
2,118,887
MERCURY CATHODE TUBE
'I‘om .lurriaansa Eindhoven, Netherlands, as
signor to N. V. Philips’ Gloeilampenfabrieken,
Eindhoven, Netherlands
Application February 15, 1937, Serial No. 125,943
In Germany February 17, 1936
5 Claims.
My invention relates to mercury-cathode tubes,
such as mercury arc rectifiers and relays, and
more particularly to the anchoring of the cathode
spot of such tubes.
To stabilize the operation of such tubes, an
choring members are used to prevent the cathode
spot from wandering over the surface of mercury
and to prevent splashing of the mercury. If the
portion of the envelope in the vicinity of the
cathode is of metal, or of glass coated with a
conductive deposit such as mercury, such mem
bers prevent the cathode spot from passing over
the surface of the mercury and reaching the
conductive wall portion. This greatly reduces
the possibility of damage to the envelope, and
especially to the metal-glass seal of envelopes
having a metal portion and a glass portion fused
together.
As the cathode spot .generally settles at the
line of separation between the anchoring mem
ber and the mercury, i. e. at the cathode line,
the surface at this point must be of perfectly
pure metal free from oxides to ensure proper an
choring action. This condition can be satisfied
in a simple manner by making the anchoring
member of a metal capable o_f amalgamating with
mercury, as this amalgamation removes the sur
(Cl. Z50-27.5)
amalgamates better than does iron or molyb
denum.
The term “dissolving speed in mercury” as used
herein and in the claims, is to be understood to
mean the loss in material of, the anchoring mem- " 5
ber due, inter alia, to amalgamation with the
mercury and to disintegration by the discharge.
per unit of time and per unit of. arc current during
the operation of the tube. .
Anchoring members of such materials have 10
suñ’iciently long life for all practical purposes,
and the settling point of the cathode spot upon
the anchoring member is formed with full se
curity and without taking additional measures, so
that the manufacture of the tube is not compli- 15
cated. Furthermore, the materials used are
standard and can be obtained at a comparatively
low cost.
As the dissolving process and any corrosion
phenomena at the settling point of the cathode y20
spot depend to a large extent upon the temper
ature, it is essential to have a good dissipation
of heat from this point. For this purpose I prefer
to locate the anchoring member in the middle
of the mercury cathode, and in good heat-trans- `25
-ierring relationship with the envelope.
?, In order that my invention may be clearly
face layer and its impurities. However, metals
which amalgamate sufficiently with mercury, for
understood and readily carried into effect, I shall
instance copper, dissolve so rapidly in mercury
accompanying drawing, in which:
especially at the physically highly-stressed point
describe same more fully with reference to the
,3o
Figure l is a sectional side-view of a mercury
at which the cathode spot settles-that the life
of the member is reduced to such extent that the
vapor rectifier embodying the invention;
tube is soon rendered unserviceable.
If, to ensure a satisfactory life, the anchoring
member is made of a material which is substan
ber according to the invention.
The rectifier shown in Figure 1 comprises an 35
envelope consisting of a cup-shaped metal mem
ber l, for instance of chrome iron, and a glass
member 2 hermetically fused together at I1.
tially insoluble in mercury, the anchoring proper
ties are either very poor, or can be developed
only with great difficulty. Thus, a completely
satisfactory solution of this problem in a simple
manner was hitherto impossible, and a suiiicient
life of such members and of the tubes could be
ensured only by using extremely pure and expen
sive metals such as platinum, or by resorting to
extremely complicated purifying methods during
the manufacture of the tube.
The object of my invention is to overcome the
above diiiiculties and to produce an anchoring
member which has a long life and satisfactory
anchoring properties.
According to the invention, I form the anchor
ing member from a metal or a metal-alloy whose
“dissolving speed in mercury” during the passage
of discharge current is less than about £5, prefer
55 ably about 1/40, of that of copper, and which
Fig. 2 is a sectional View of an anchoring mem
Disposed in the bottom of member l is a mercury
cathode 3, whereas a main anode 8 is supported 40
from the lower' end of a conductor 6 Whose upper
end is secured to a metal disc 4 hermetically
sealed in glass portion 2 and carrying a terminal.
Supported from conductor 6 and surrounding
anode 8 is a cylindrical screen II serving to 45
protect the higher internal surfaces of portion I
and seal Il from the detrimental effects of the
discharge.
Supported by screen Il, preferably of sheet
molybdenum,'is an insulating tube 20 through 50
the bore of which extends a conductive rod I9
carrying on its lower end an auxiliary anode 9.
The anode 9 is adapted to be moved in the direc
tion of the double-headed arrow, and for this
purpose the upper end of rod I9 carries a plunger 55
2
2,118,887
I8 of magnetic material electrically connected`
through a compression spring 22 to a core 2|
of a magnetic material. Core 2l is supported
`from the lower end of a conductive rod 1 secured
to a disc 5 hermetically sealed in glass portion 2.
Outside the envelope and surrounding core 2I
is coil III which serves to raise anode 9 from the
surface of the mercury.
Surrounding metal member I is a cooling jacket
10 I 2 having an inlet opening I3 and an outlet open
ing I4, and through which a. circulating cooling
medium, such as Water, is circulated in the direc
tion of the arrows during operation of the recti
ñer. Jacket I3 is secured to metal member I by
16 a copper bolt I5 secured, for instance, by Welding
the appended claims to be construed as broadly
as permissible in view of the prior art.
What I claim is:
1. A mercury-cathode tube comprising an en
velope having a wall portion of mercury-resistant
metal forming part of the bottom thereof, elec
trodes within said envelope including a mercury
cathode Within the bottom part, and a massive
cathode-spot anchoring member partly Within
said mercury cathode and carried by said metal
wall portion, said member consisting of a metal
lic material substantially of nickel.
2. A mercury-cathode tube comprising an~ en
velope having a wall portion of mercury-resistant
metal forming part of the bottom thereof, elec
to the bottom of member I and serving to supply ‘ trodes within said envelope including a mercury
cathode within the bottom part, and a massive
current to cathode 3.
Centrally disposed in the mercury'cathode 3
is an anchoring member I6. According to the
20 invention, I form member I6 of a metal or metal
`alloy Whose “dissolving speed in mercury” dur
ing the discharge of the discharge current is at
`the utmost T‘mfand preferably about 1/40, of
that of copper, :and which'amalgamates better
Vthan does iron or molybdenum. As a suitable
material for this purpose I prefer to use nickel
or an --alloy substantially constituted by this
metal.
To insure good dissipation of heat from mem
berV I6, the entire lower surface thereof is in di
rect _metallic contact with the bottom of the
memberwl, and for instance, Welded thereto. The
member I5, which is of large size and of a good
.heat~.transmitting material, such as copper, is
secured, for instance welded, to the lower surface
of .member I land thus aids in the dissipation of
.heat from the anchoring member I6.
As shown in Figure 1, member I6 is shaped as
a disc; -however it maybe given various other
:40 shapes, for instance asa ring 23, as shown in
Fig. .2. The cathode line inside a ringshaped
member,».in contradistinction to that around a
disc shaped member, will show a tendency to
grow longer as a result of the gradual erosion of
the `member so that its current carrying capacity
45
is not impaired with the increase of the age of
.the tube. Furthermore, >member I6 may have
aroundedor roughened upper surface, and it is
sometimes >of advantage to use a porous struc
"50
ture.
While I have described my invention in con
nection with speciñcexamples and applications,
I doV .not Wish >to be limited ythereto but desire
cathode-spot anchoring member of nickel partly
within said mercury cathode and carried by said
20
metal wall portion.
3. Afmercury-cathode tube comprising an en~
veloperhaving a wall portion of mercury-resistant
metal forming part of the bottom thereof, elec
trodes within said envelope including a mercury
cathode within the bottom part, and a massive 25
cathode-spot anchoring member partly within
said mercury cathode and secured to said metal
wall portion in good heat-transferring relation
ship, said member consisting of a metallic ma
terial substantially of nickel.
30
4. A mercury-cathode tube comprising an en
velope having a wall portion of mercury-resistant
metal forming part of the bottom thereof, means
for artificially cooling said metal wall portion,
electrodes ~within said envelope including a mer
cury cathode Within the bottom part, and a mas
35
sive cathode-spot anchoring member partly Within said mercury cathode and secured to said wall
portion in good heat-transferring relationship,
said member consisting of a lmetallic material 40
substantially of nickel.
.5. A mercury~cathode tube comprising an en
velope having a wall portionof mercury-resistant
metal forming part of the bottom thereof, elec
trodes withinvsaid envelope including-a mercury 45
cathode within the bottom part, and a massive
cathode-spot anchoring vmember partly within
said mercury cathode andcarried by said metal
,Wall portion, said member having an annular
shapeand consisting of a metallic material sub 50
stantially of nickel.
rI'OM JURRIAANSE.
Документ
Категория
Без категории
Просмотров
0
Размер файла
312 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа