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Патент USA US3021417

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Feb. 13, 1962,
3,021,407
_ J. E JENNINGS
VACUUMIZED ELECTRIC SWITCH
Filed Sept. 16, 1958
‘INVENTOR.
JO EMME TT JENNINGS
“61611044”
his AT TORNE Y
'
3,021,407.
rice
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Patented Feb. 13, 1962
"
States Patent
1
2
.
integral union, and therefore hermetic seal, is effected
r
3,021,407
This integral union is formed by a copper skirt of sub
‘
VACUUMIZED ELECTRIC SWITCH
stantial thickness throughout, brazed at its inner edge
to the metallized edge of the ceramic shell, and at its
outer edge integrally united to the plate, by a steel ?ange
_Jo Emmett Jennings, San Jose, Calif., assignor, by mesne
assignments, to Jennings .Radio Manufacturing Cor»
poration, San Jose, Calif., a corporation of Delaware
Filed Sept. 16, 1958, Ser. No. 761,315
8 Claims. (Cl. 200-144)
My invention relates to vacuum'switches and especially
at the upper end of the shell, and directly at the lower
,
end.
‘
At the upper end, the freeledges of ?ange and skirt
are contiguous, and extend around the cylindrical shell
on the outside at a short distance therefrom, so that the
to such switches of large diameter and very large ca
pacity.
One of the principal objects of the invention is the ,
provision of a vacuumized switch having an envelope
two edges are readily joined by a heliarc weld, and as
easily cut apart when need‘arises. The free portion of
the skirt preferably conforms substantially to a conical
plate, ?aring outwardly and downwardly. At all points
large enough to holdthe heavy conductive structure and
contacts required for carrying currents up to 10,000 15 the sealing skirt is a" thickness amply su?icient to with
amperes or more.
'
-’ I
With the development and use of electric power, there
has been demand for ever larger vacuum switches to
handle the increasing current loads. Expanding the
diameter and capacity of vacuum, switches has been
severely hampered by the inherent weakness of the metal
to-glass or conventional Housekeeper seal. Any increase
in size of a vacuumized shell orenvelope results in a
directly proportional increase in total pressure exerted
stand any probable stress placed upon it in normal use
of the switch without damaging strain. The lower end
of the ceramic shell is provided with a skirt which also
seals it integrally to vthe lower end plate, but in thiscase
the skirt is not‘ intended to be severed to free the end
but only to provide an all-metal seal, and avoid a trap
for external moisture and dirt.
Within the envelope formed by the cylindrical shell
and end plates, switch elements are arranged. A ?xed
by the atmosphere on all exposed surfaces of the en 25 contact is mounted within vthe shell on one end plate;
and an axially aligned mobile contact is slidably jour
velope; and on an eight inch generally cylindrical evac~
naled on the other end plate, a bellows being interposed
uated envelope, the‘ pressure tending to crush in each
between bearing and mobile contact to preserve the
end amounts to more than 700 lbs. This is greatly in
vacuum within the shell.
'
excess of pressures which can be borne by switches hav
The mobile, contact of the switch is ?xed on the inner
.'ing conventional metal-to-glass unions or'seals.
end of an operating stem within the vacuumized en
' In addition to stresses imposed by atmospheric pres
sure, the seal structure must carry stresses‘imposed by
the weight, sometimes considerable, of operative parts
mounted on the ends,’ and also the shock of closing con
velope and in axial alignment with the ?xed contact. The
stem extends'out of the‘ open end of the bellows in a
~ portion adapted'for‘ connection to a conductor; and is
tacts and the outward jerk of opening contacts.
35 connected to a solenoid or other operator by an in
sulator link.
,
1
\ The‘ primary object of my invention therefore is to
.Atmospheric pressure tends to close the mobile contact
provide means whereby a large vacuumized nonconduc
upon the aligned ?xed contact to close the circuit through
Jtive cylindrical shell can be closed hermetically at its
the switch. The solenoid or other operator when ener
ends, and having strength in the sealing ‘means amply
sufficient to carry the heavy loads imposed by the atmos 40 gized, pulls the mobile contact away from the ?xed con
' tact to open the circuit. The bellows permits both move
phere and its size. In a main embodiment of myv inven
ments without break in the vacuum of the enclosing
tion as shown in the drawing, the ceramic shell is sealed
‘directly to. the metal end closure structure by a heavy
In detail my switch comprises a cylindrical ceramic
gauge copper plate, so that at no point in the entire
shell 2., around the upper metallized edge 3 of which is‘
envelope are weakening strains imposed by atmospheric
brazed a skirt 4 of copper having substantially an even
pressure or by the stresses of expansion and contraction.
thickness throughout. The copper skirt ?ares outwardly
The heavy gauge copper plates at top and bottom are
from the shell, in a substantially conical conformation,
.of different shape, and have certain different functions’
terminating ina free edge 5, lying snugly against the
and purposes despite their common purpose of providin
inner surface of the cylindrical steel ?ange 6, brazed into
vital eleinents‘in an all-metal seal.
‘
a
y
‘
50 a groove in the lower face of the upper plate 7. The
Another object is the provision of a vacuumiz'ed switch
contiguous edges of ?ange and skirt are readily acces
of very large capacity housed in a cylindrical dielectric
sible and may be readily brazed together to form the
shell, closed hermetically at each end by a simple plate
joint 8 by the heliarc process. They are also readily
-.5tructure hermetically united to the shell by all-metal
sealing means including a readily accessible joint at 55 separated if necessary to give access to the switch parts.
envelope.
which the seal may be broken to give access to the
interior of the switch, the seal then being capable of
being reformed, and the switch envelope again vacuum
, ized for further use.
I‘
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i
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‘
I
Mounting holes 9 are formed about the rim ofeach
end plate; and a metal tubulation It) is brazed to the
plate 7 in continuation of the passage 12 by which‘ the
switch envelope is connected to the processing pump.
A heavy copper cylindrical mounting block 13 is brazed
Other objects will be brought out in the following 60
into a recess concentricallyformed on the inside face of
‘description of the invention. I do not limit myself to
the upper end plate; and on its inner face is ?xed the
the showing made by said description and the ‘drawings,
since I may use variant forms of the invention within
the scope of the appended claims.
,
‘With reference to the drawing which is approximately
‘full size, the ?gure is a half-sectional view of a switch
embodying my invention. A portion of the ?gure is
omitted to reduce its height. I The switch is shown in
. closed position.
i
'
a
tungsten contact or electrode '14. ,These heavy parts
thus provide ample conduction‘ for heavy currents and
‘escape for generated heat. A cap screw 15 provides
means for connecting the ?xed end of the switch to a
conductor 16.
I
It will be observed that this structure, provides a her
metically tight upper end for the shell; and that the
1tion comprises a vacuumized ceramic cylindrical shell,
by‘ atmospheric pressureare carried by
70, ‘stresses‘imposed
the all-metal seal 47-6 and by the end‘ plate 7, which
‘,ClOSCd at each end by a metal cover plate with which an
in addition supports the mounting block and ?xed con
. - In broadly descriptive terms, the switch of my inven
3,021,407
3
A.
the apertured lower plate, but leaving the lower all-metal
tact. It also carries the shock and thrust of the closing
contacts.
seal between shell and lower end plate intact.
Access to the envelope may also be had by severing
the union between the ?ange 6 and skirt 5, ?rst discon
necting the conductor 16. With the loss of the vacuum
the upper end plate, together with its connected mount
ing block and tungsten contact may be lifted off.
With reassembly of the parts and reforming the heliarc
‘joint or joints opened, the tubulation can be again con
In the lower portion of the shell is the mobile tung
sten contact or electrode 17 mounted in the head 13 of
thesolidcopper stem 19. The stem is slidably journaled
in‘ a ?xed bearing tube 21 having a wide ?ange 1/2 and
concentrically arranged on and secured by screws 23 to
‘the lower end plate .24 of which it forms the central hear
ing portion.
Expansible means, preferably a metal bellows 26 is 10 nected to the pump and the unit processed as before.
I claim:
interposed between the lower end plate and the stem 19
to‘ permit axial movement of the stem to open and close
1. In a vacuumized electrical implement, a dielectric
the switch without destroying the vacuum within the en
velope.
cylindrical shell, an end plate having a central opening,
.
means integrally uniting the end plate to one end of
All-metal sealing means is provided at the lower end
the shell, a bearing extending through said central open
ing of the plate into the shell and having a ?ange ?xed
of the shell 2 for hermetic securement to the lower
end, plate, so that stresses caused by expansion and con—
to the end plate and extending across the central open
ing, a stem journaled in the bearing, and a bellows at
one of its ends integrally connected to the stern and at
its other end integrally connected to and functionally
traction are accommodated in a manner somewhat simi
lar to that found in the upper all-metal seal. The plate
is provided wtih a circular and concentric groove 27.
An annular copper plate 28 having a short outer periph
severable from the end plate, said central opening of
eral ?ange 29 and a central downwardly extending bead
the end plate being larger than the largest diameter of
31, is brazed to the metallized lower edge of the shell,
the bellows to permit passage of the bellows and attached
the bead lying loosely in the groove 27 and the ?ange 2.9
stern therethrough in assembly and disassembly.
brazed into a corresponding shallow groove in the plate. 25, 2. In a vacuumizedelectrieal implement, a dielectric
An annular ring 32 may overlie the upwardly opening
cylindrical shell, an end plate having a central opening,
bead if desired to prevent accumulation therein of for
means integrally uniting the end plate to one end of the
eign matter.
shell, a bearing having a ?ange ?xed to the end plate
,
_
Brazed to the inner periphery of the apertured lower
plate is a shield .33 surrounding the bellows and pro
tecting itfrom, bombardment and injury by the ?ying
hot tungsten particles at times thrown off the contact
points of the switch. The lower edge 34 of the shield
projects past, the narrowed inner edge 36 of the plate
so that a free margin is left under the overlying bear
ing‘?ange 22 for convenient integral union as by heliarc
to the adjoining lower ?ange 37 of the bellows. This
integral union 38 unites the bellows to the lower plate.
The upper end 39 of the bellows is brazed to the upper
30
and extending across the central opening, a ‘stern jour
naled in the bearing, an annular ?ange integral with the
end plate and extending into the opening, and a ‘bellows
extending intothe shell and at one of its ends integrally
connected to the stem and at its other end terminating
in an annular ?ange contiguous to the end plate annular
?ange and integrally united therewith, said central open
ing of the end plate being larger than the largest di
ameter of the bellows to permit passage of the bellows
and attached stem therethrough in assembly and disas
sembly.
_
.
end of the stem under the head 18 along with the battles 40
3. In a vacuumized electrical implement, a dielectric
or shields All and 42, the latter having the outwardly
cylindrical shell, an end plate having a central opening
and upwardly ?aring ?ange 43. The shield 41 is pro
with an annular relatively thinner ?ange extending from
vided with a downwardly directed ?ange 44- ending closely
the edge thereof into the opening, means integrally unit
adjacent to the rim 4-6 of the surrounding shield 33.
ing the end plate to one end of the shell, a bearing hav
The shape, size and placement of the three shielding 45 ing a ?ange ?xed to the end plate and extending across
surfaces 33, 44 and 43 are such that in operation of the
the central opening, a stem journaled in the bearing
switch, the ?ying high speed hot particles of tungsten
torn oil the switch points are prevented from striking
the bellows. Only relatively few slow moving in?nitely
small particles will drift at low velocity through the very
narrow annular space between the shields 33 and 44.
The stem 19 extends downwardly out of its bearing,
in a portion 47, adaptedto receive a clamp connector
48 for the direct and positive connection of the conduc
tor 49 to the stern and tungsten contact, thus avoiding
any sliding connection through the switch capable of
spark-welding relatively moving parts together. The end
and extending as a connector stud outside of the ?ange,
a bellows extending into said shell and enclosing said
bearing and at one of its ends integrally connected to
the stem and at its other end integrally connected to the
thinner ?ange of the end plate, and dielectric means
?xed to the connector stud for securing the stud to an
operator for the stem, said central opening of the end
plate being larger than the largest diameter of the bellows
to permit passage of the bellows and attached‘ stem there
through in assembly and disassembly.
,
4. In a vacuumized electrical implement, a dielectric
of the stem includes a brass bushing 51 brazed exter
cylindrical shell, an end plate having a central opening,
nally to the stem, and threaded internally to receive a
means
integrally uniting the end plate to one end of the
threaded stud 52 which rigidly connects the stem to the
60 ‘shell, a bearing having a ?ange ?xed to the end plate
dielectric link 53 of Te?on or equivalent non-conduct
and extending across the central opening, a stem jour
ing material. A rod 54 threaded into the outer end of
the link 53 completes the connecting link between the
naled in the bearing and extending therebeyond into the
shell, a bellows at one of its ends integrally connected
to the stem beyond the bearing and within the shell and
The respective diameters of the three shields is also 65 at its other end integrally connected to and functionally
severable from the end plate outside the shell, and an
important because in the event that it is necessary for
electrode ?xed on the inner end of the stem.
inspection or repair to gain access to the interior of the
5. In a vacuumized electrical implement, a dielectric
envelope, the clamp 48 and conductor 49, and the link
cylindrical shell, an end plate having a central opening
element $3 are disconnected; and the screws 23 removed. 70 bordered by an exposed ?ange, means integrally uniting
The bearing tube 21 with its ?ange 22 can then be
the end plate to one end of the shell, a bearing having
stem 19 and the operator which may be a solenoid or
other appropriate means.
drawn oil of the stem.
-
By severing the union 3%, the vacuum is destroyed
a ?ange detachably ?xed to the end plate and extend
ing across the central opening over the exposed ?ange,
and the assembly of bellows, stem and shields 43 and
a stern journaled in the bearing, a bellows at one of its
44 may then be withdrawn from the envelope through 75 ends integrally connected to the stem and at its other
‘
‘ 3,021,407
6
end integrally connected to and functionally severable
from the exposed ?ange, a substantially'cylindrical shield
mounted on the end plate around the bellows, and a
circular shield mounted on the stem and having a maxi
mum diameter less than the minimum diameter of the
central opening through the end plate when the integral '
connection between bellows end and exposed ?ange is
"severed.
the shell and having one periphery integrally connected 2
to the edgeof the shell‘ and the other periphery integrally '
connected to the closing plate ‘with ‘the head in the
groove.
8. An hermetic seal betweenthe metallized terminal "
end surface ofa hollow ceramic shell and a metal end, ‘
plate, comprising a radially, shaped annular ring sur
rounding the shell and integrally connected along one
of its edges with the end plate, and the other edge being
6. In a vacuumized electrical implement, a dielectric
cylindrical shell having its end edges metallized, an end 10 integrally united to the metallized terminal end surface
plate overlying the upper end of said shell, an end plate , of the shell and lying between the terminal end surface
and the end plate, said annular ring closely spacing .
having a centralopening therein and overlying ‘the lower
I the end plate from the terminal end surface of the shell‘
end of said shell, an expansible annular skirt outside
by approximately the‘ thickness of said annular ring.
each end of the shell and integrally connected at its
inner periphery to the shell end edge and at its outer 15
‘References Cited in the ?le of this patent
periphery to the end plate, an annular relatively thinner
_ UNITED STATES PATENTS >
?ange integral with the lower end plate and extending
into the opening, a bearing having a ?ange ?xed to the
1,011,160
Co?in _‘___‘ ___________ ..- Dec. 12, 1911
lower endyplate and extending'across the central'open
1,905,751
Rankin _________ __'_.__.._ Apr. 25, 1933
ing, a stem journaled in the bearing, a bellows at one 20 2,314,266
of its ends integrally connected to the stem and at its
2,326,074
other end integrally connected to the thinner ?ange of ' 1 2,773,154
Williams ________ __‘__'_.._ Dec. 4,1956
the end plate, and aligned electrodes within the shell and
2,794,101
Jennings -e. ___________ __ May 28, 1957
mounted respectively on the upper end plate and on the
2,854,550
Gerth et al, ___________ .__ ‘Sept. 30, 1958
stem said end plates being spaced closely to the respec 25
2,863,027
Jennings _; _________ __'__ Dec.’ 2, 1958
Beam ______________ _;._ Mar. 16, 1943
Slepian ..___ __________ _._ ‘Aug. 3, 1943
tive end edges of the ‘shell by approximately the'thick
2,892,912
Greenwood et al _______ __ June 30, 1959
ness of said skirt at its inner periphery.
2,900,476
2,916,577
Reece ____,_.~.,. ________ __ Aug. 18, 1959 i
Smith ________________ ..._ Dec. 8, 1959
2,920,169
Jennings _____ -2 _______ __ Jan. 5, 1960
563,140
' Germany _________ .._‘.___ Nov. 3, 1932
‘
7. An all-metal seal for a vacuumized envelope hav
ing a dielectric cylindrical shell closed by a metal plate
having an upwardly opening groove therein concentric 30
with the shell, comprising a metallized edge on the shell,
and an annular beaded metal skirt adjacent the end of
FOREIGN PATENTS
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