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Патент USA US2132922

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Oc'f. 11, 1938.
' 2,132,922
Filed April ll, 1936
2 Sheets-Sheet 1
_ /Z 21 27 28
„1,114 willi”,
Oct. l1, 1938.
P. s'. BEAR
Filed April 11, 1936
2 Sheets-Sheet 2
1. .?3. . .
Patented Oct.’1`1„1938
JUN 3- 1941
" 2,132,922
Paul S. Bear, Elkhart, Ind., assignor, by mesnc
assignments, to Bucklen-Bear Laboratories,
Inc., Elkhart, Ind., a corporation of Indiana
Application April 11, 1936, Serial No. 73,883
24 claims.' (cl. zon-152)
tact, as distinguished from the 'substantially
This invention‘relates to switches, and more
particularly is directed to switches of the metal
point contact that occurs when two curved sur
faces are brought into contact.
envelope type employing mercury as the con
tactor between spaced metallic electrodes.
Also, heretofore, when the switch' was slowly
In my prior copendlng application, Serial No. tilted toward circuit closing position, consider- 5
745,842, September 28, 1934, I have disclosed a f able frying and sputtering of the contact surfaces
switch construction employing a cup-shaped occurred as they moved into engagement. With
metal shell of stainless steel or the like, having the present construction, a slow motion closing
an enlarged open end receiving a refractory or of the circuit is possible without these attendant
lil ceramic member sealed in the end of the shell
disadvantages, and the capacity of the switch is >10
and supporting a second electrode in spaced re
considerably increased without any danger of
lation to the shell. The present invention con
such frying or sputter-lng. Even on lamp loads,
stitutes a modification in the design and assem
where the closing arc is excessive, tending to
bly of such type of mercury switches for imparting produce overheating of the interior of the switch,
1.; to such swìtches’improved operating character
the present design of switch takes care of such -15
loads easily without any material heating, and ` _c
I have .found that a mercury switch can- be ‘ operates under such loads at temperatures only
provided having greatly improved operating
slightly above the adjacent room temperature.
The mounting of the ceramic insert Ain the
switch envelope as disclosed in the present con- 20
struction is such that no portion of the ceramic
characteristics by treatment of the mercury it
self, as described in the copending application
of lmyself and Herbert E. Bucklen, Serial No.
67,816, filed March 9, 1936. With this im
proved mercury contacting body, and the em
ployment of a¿ liquid alkaline 1111,' such as trl
is placed under tension, the sealing gasket and
the support of the ceramic in the metal envelope
being such that the ceramic is subject only to
compression stresses. This materially lessens 25
any danger of cracking of the ceramic during
ethanolamine, a switch can be produced which
is capable of carrying relatively high current,
and which can give consistent repeat perform
ance by reason of the retention of a‘stable body
operation of the switch when internal pressures
may be developed due to heating or the like.
Another feature of the present invention is the
of mercury in contact with the second electrode. `
30 Reference is made 'to my copending application- positioning of the ceramic in thermal contact 30
,Serial No. 53,146, ñled'December 6, 1935, for a with the metal envelope, whereby any heating of
full disclosure of these features.
the ceramic will be dissipated by -radiation from
The present invention, in its preferred form, is the-external surface of the envelope. This ma
directed to the provision of a metal envelope type terially increases the capacity of the switch to
high currents, since the heat generated upon 35
- of switch having an internal construction such
that a greatly increased area of contact between
the two contacting bodies of mercury, or between
a moving body of mercury and a stationary elec
making and breaking of contact ,in a high ca
pacity switch is thus readily dissipated externally c
of the switch.. In this connection, I employ a
trede, is produced, whereby the capacity of the
refractory material that is thermally conductive,
so that no localized heating of any portion of the 40
40 switch is increased to an. extent not hitherto
possible in switches of this type. This is accom
plished by providing a polygonal-shaped en
velope with a ceramic,insert having a planar
runway across which the moving body of -mer
ceramic is possible.
The use of a limited alka-
line' liquid ñll is also instrumental in affording
dissipation of heat to all portions of the switch
The ceramic employed in the present switch 45
' cu-ry moves into and out of contact with a re
tained stable body of mercury which is in contact is designed in such >manner as to provide a. rel
with the electrode. The stable body of mercury atively long leakage path between the central
`lies in a straight line along a sharp cutting edge ' electrode supported in the ceramic and the sur
rounding wall of the metal envelope, thereby
and presentsy an area. of contact which is con
50 siderably increasedover that provided with the eliminating any tendency of shorting the circuit` 50
usual ' cylindrical type of metal switch. «In between the electrode and the envelope across
effect, I obtain a straight line advancing edge the ceramic externally of the switch chamber.
cf mercury and vretain a straight line contacting By the use of the present construction, produc
ing the elongated leakage path, I also provide
surface of mercury whereby a greater cross
55 section of mercury comes into simultaneous 99D- Ä for the resilient gasket which seals the ceramic u
2,122,922Figure 4 shows the mounting of a switch em
in position in the envelope to engage the ceram
ic in such manner as -to subject the same to com-l
pression, so that' any internal pressures devel
oped in the throat of the ceramic serve onli7
in overcoming this compression stress, and do not
place'any tension _upon any portion of the ceramic.
bodying the principles of the present invention
>stresses being placed upon the ñber members
within a moi-ded case;
Figureâ is ,a sectional view taken substan
tiallïvì on line 5-5 of Figure 4; '
Figure 6 is an elevational View of the contact
The present construction is also advantageous ~ lug retaining washer shown in Figure 4;
Figure 'l is a modified form of electrode con
in that the diameters of the electrode support
ed in the ceramic and of the retaining ring struction; and
'Figure 8 shows a switch of the present inven 10
l10 which is employed to compress the gasket during
the assembly of the’switch prevent any shear tion embodied in a water jacket heat dissipating
enclosing the outer face of the ceramic. This
prevents, to a large extent, any danger of the
15 internal pressure being such as to force the elec
trode axially outwardly of the switch envelope,
since the intermediate gasket means between the
outer face of the electrode and the compression
ring will be subjected to stresses other than
straight shearing stress, and consequently have
Referring now in detail to the switch shown
in Figure l, I provide a cup-shaped metallic en
velope Il) having the enlarged cylindrical por 15
tion I2 jointed to the main portion of the en
velope by the frusto-conical section I3. A suit
able ceramic insert I4, preferably formed of
porcelain, and having an cuter deñning surface
conforming to .the internal surface of the por 20
a much greater resistance to such movement of ` tion I3 of the enveiope, is inserted into position,
the electrode.
My invention also contemplates the provision
of a switch assembly havingA a novel type of con
tact lug- retaining washer, the entire assembly
its position being determined with respect to the
portion I0 of the envelope by means of the align
` ing groove I5 -formed in the ceramic insert and
engaging over the struck up boss .I6 in the en
being capable of being enclosed within a mol-ded
in the case, or at points 'disposedein any angular
ing body of mercury I1, vwhich mercury may be 30
. The portion I0 of the -enveloperis preferably
case formed of a phenol condensation product
or the like, and capable oi' adjustment so that " `square in section, although it may be of any
the leads may be brought out at the same point desiredpolygonal shape, and contains the mov
_ relation, as desired.
cleaned and treated in the manner disclosed in '
A Astill further advantagesecured by the pres
ent invention is the provision of a construction
such that maximum contact area is provided be
tween the retained body of merc
and the sur
face of‘the electrode, whereby he resistance to
current passage between thelmercury and the
electrode is reduced, so that a suñ‘icient area of
contact is provided to prevent any overheating
at this portion A,of the switch. ,
above mentioned copending application.
The ceramic» I4 is provided with an inclined
frusto-pyramidical opening I8, -terminating at
the smaller end in a sharp cutting edge i9 de 35
vfined by the walls 20 which extend normal to
-the axis of the ceramic. A suitable electrode
22, which is in the shape of a circular disc
member and which is provided with the extend
ing stud portion 23, isspaced outwardly of'the 40
‘ .
I also contemplate, in the present switch con
struction, the enclosing of the switch within a
walls 20 and closes the outer end of the opening
water jacket or the like, whereby the switch
'I'he ceramic I4 is provided with an axially
extending annular ñange 24 within which the
electrode 22 is seated, and a suitable cup-shaped 45
resilient gasket 25, which may be formed of syn
thetic rubber or the like, is disposed about the
extending portion 23 of the electrode and has
the annular flange portion 26 disposed about the
flange 24 of the ceramic `and in engagement with 50
the internal surface of the portion I2 of the en
may operate under heavy loads and any heating
45 which' may occur will be readily carried away
by the circulating water in direct contact with
the external surface of the metallic envelope.
I also provide a Vmetal envelope having two
diameters, whereby the enlarged portion of the
envelope is adapted to receive the ceramic in
„50 sert and the sealing means, while> the smaller
portion oi’ the envelope is used to carry the mov
ing body of mercury, andi'orms the other elec
trode. By the use of this construction, I provide
55 for adequate sealing and closing meansî with
suflicient electrical clearance between the stud
and the shell, and yet produce economy in the
amount of mercury'which must he employed in
the switch, as well as keeping the size and weight
of the switch at a minimum.
velope. The gasket is compressed against the
internal surface of the portion I2 of the envelope
and against the external- surface of the ñange
24 by means of the fiber washer 21 which is car 55
ried about the stud 23 and which engages the
rear face of the gasketJ 25. v'Ifne' washer 21 is
urged inwardly by means of the compression ring
28, formed of any suitable material, which is
L moved inwardly by beading over the end 29 of 60
Other objects and advantages of the present ' the portion I2 of the envelope. This beading or
spinning‘over of the end 29 compresses the gas
-invention will appear more fully from the fol
ket` 25 in position to seal the space between the
lowing detailed description, which, 'taken in con
junction with the accompanying drawings, will
65 disclose to those skilled in the art the preferred
construction _and operation of the present in
- between the internal surface of the ñange 24 and
In the drawings: ,
Figure 1 is a vertical sectional view through
70 ' aswitch embodying the principles of the present
Figure '2 is a vertical sectional vi'ew through
a modified forml of switch;`
Figure 3 is a sectional‘view taken substantially
on line 3-3 of Figure 2;
external surface of the ceramic and the internal `
surface of the portion I2 of the envelope, and 05
to also seal any clearances which may be provided
. ,
the stud 22.
It will be noted that the leakage path between
the portion I2 of the envelope and the electrode 70
22 is increased by this construction, and thus the
danger of shorting the switch by' a short circuit
flash-over betweenV the stud 22 and the portion
I2 of the envelope is substantially eliminated.
The stud portion 23 of the electrode 22 is pro- 75
vided with a suitable nut 30 threaded thereon,
which engages a washer 32 that serves to com
press the washer 21 against the gasket 25. If
desired, arsuitable insulating spacing bushing "
3l may be provided to position the washer and
nut out of a possible- ilash-over >position with
‘respect’ to the vcompression ring and edge of the
I preferablyy form the ceramic Il of porcelain,
10 inV that porcelain is a thermal conductor having
I3 in the recess formed between the wall 2l and
the face of the velectrode 22 to be also maintained
in a straightfline. Thus, the meeting edges of
the two bodiesfof mercury produce a straight line
contact across the entire width of the opening. 5
This materially increases the cross-sectional area
of mercury which comes into contact, -thereby
allowing a much heavier current to be passed
through the contacting surfaces. The capacity
of the switchis thereby materially increased.
The rectangular pocket formed between thel
a conductivityv rating which, while not as good
as iron, is~ in close proximity thereto. Further
electrode 22 and the walls 20 in the construction
more, porcelain is free from metallic oxides that vshown in. Figure l retains a body 4of mercury
give ofi’ free oxygen in areasV subjected Vto anr which is of a width such as to have inherent
electric arc, and therefore the use of a porcelain stability. The advantages of the retention on~
ceramic insures that no impurities will'bevin
such a stable body of mercury whose meniscus
troduced into the interior of the switch envelope l‘rises above the sharp cutting edge over which
which might prove deleterious to switch opera
contact is> made and broken have lbeen pointed
tion. Certain ceramics, such as those known out in detail in my copending application, Serial '
20 commercially as “Alsimag" andv “Isolantite”,
No. 53,146, filed December 6, 1935.
while perfectly adapted for use as far as mechan
I have ~found that by changing from a cylin
ical fitting _of parts is concerned, are not desir
drical form of switch to the polygonal envelope
able in alswitch of this construction, since they type of switch, an increase. in effective contact
are relativelyv poor thermal-conductors, that is, area, when lthe envelope type is of a diagonal di
excellent thermal insulators. This means >that . mension substantially equal to the diameter of 25
when an arc is impinged upon a given point re- .
the cylindrical type, is employed, is increased
peatedly in a ceramic of this latter type„the
approximately 300% over the area provided in
heat builds up at that point and is not conducted a cylindrical type of switch of the same external
away to any other portion of the ceramic. As dimension. 'I'his means that a material reduc
` this heat approaches a given point, the metallic tion inthe heating caused by the arcing pro 30
oxides in. this type of ceramic are reduced, and duced at the contact is effected, and also, currents
the oxygen attacks the mercury and the unre
of much greater capacity can behandled by a
duced particles that spall oil' are floated on top~ switch of this present construction.
of the mercury, or form an emulsion with thel .Referring now in detail _to the construction
C: L: triethanolamine. Continued usagel of ceramics
shown in Figure 2, this ilgure discloses a modified as
of this type erodes a channel through the dam form of- switch in which the metal envelope I0’ is
forming the retaining recess until the -retaining provided with a normally extending shoulder I2’
recess no longer is capable of retaining any mer
and the cylindrical portion I3', the square shoul- `
cury. On the other hand, porcelain, being a der ll’pserving as an abutment for limiting the
40 good thermal conductor, no localized points’ of inward movement of the .ceramic I4'. The re 40
heating will build up, since the porcelain will maining details of the construction arev substan
rapidly conduct the heat away from the localized tially as described in connection with Figure 1,
point oi heat generation to all portions of the
. ceramic, and this ceramic being in thermal con
tact with the _metal envelope surrounding the
-^ same, the heat will be readily dissipated to ad
jacent portions of the switch. Also, it is to be
noted that porcelain has a smaller thermal ex
pansion than iron. Consequently, during oper
the ceramic I4' being provided with a square type
of'opening Il having> planar inclined runway
surfaces, the ceramic Il’ being aligned with re 45
spect to the square portion III' of the envelope by
means of the aligning pin 35 engaging in a suit-4
able recess formed in the ‘ceramic Il’. Similar
reference numerals have been employed to indi
ation of a switch in which the porcelain is dis
cate similar parts of the construction.
As‘will be apparent from the structure shown
posed in direct contact with the iron, any de
velopment of heat will result in expansion of the in Figure 3, the body of mercury I1 moves up
surrounding iron away from the porcelain. This lthe planar inclined surface I8 into contact with
allows ñuid under pressure to enter the space the retained body of mercury 33 retained in the
'between the ceramic and the surrounding iron rectangular groove formed between'the face of
envelope, consequently balancing the pressures the electrode 22 and the wall 20 deilnìng the sharp
cutting edge I9 at the inner end of the _inclined
tension stresses are produced which might tend surface I8. 'I'he entire width of the surface I8 is
to crack the porcelain.
therefore occupied by the advancing edge of the
body of mercury I1, and the entire width of the 60
I iind that ample sealing is secured by employ
ing a gasket having only a relatively short skirt or cutting edge- I9 is also contacted by the retained
ilange 26, which seals the outerface of the por _ body o'f mercury 33.' Consequently, as the moving
celain and4 yet does not confine any heating of body I1 moves into engagement -with the body 33,
the porcelain so that dissipation is eliminated. two straight line contact surfaces are provided
It is desirable that- any heat generated due to which materially increase the .contact area or
arcing within the switch be dissipated as rapidly cross section of mercury coming into simultane
ous contact. >T'his serves to reduce the resistance
as possible through the porcelain to the enclos
to making and breaking of the circuit, and at the
ing metallic envelope.
upon opposite sides of the ceramic so that nc
By the use of a polygonal shaped envelope in
70 _which the body of mercury I1 is capable of mov
ing, I provide .for a substantially straight line
advancing edge of the mercury as it moves up
same 'time providesv suiilcient mercury so that a `
much greater current can be controlled by the
I have found that if the depth of the groove in
war'dly over the inclined planar surface Il. l which the retained mercury 33 is disposed is not
Similarly, the use of a square opening in the of a predetermined dimension', overheating will
75 ceramic permits the retained body of mercury occur due ‘to the relatively small contact area be-’ï 75S
tween the retained body of mercury 33 and the
surface of the electrode 22 with which the mer
cury is in contact. In order to prevent any such
overheating and to insure that sufficient metal
in to mercury contact is provided for all currents
lwhich may be handled by the switch, I have
provideda construction such as shown in Figure
'1 `in which the ceramic 48 is provided with the
rearwardly extending annular flange 42 defining
with the inclined planar surface 43 a square
shaped grooveextending about an annular groove
v44. Within this’annular groove 44 I dispose a cup
shaped electrode 45 'having the cylindrical flange
portionv46 lying in and determining the outer
periphery of the' groove. Disposed within the
groove 44, and retained between the inner face of
the electrode 45 and the inner defining wall of the
groove is a body of mercury 41 which has a sub
stantially increased contact area in engagement
20 with the surface of the electrode 45. Consequent
ly, the mercury to electrode contact area is in
creased to an- extent such that no overheating
can occur because of the passage of higher cur
rent of the body of mercury 41 to the electrode 45.
'_I‘he electrode 45 is provided with a stud 48 ex
tending rearwardly therefrom, and the usual re
silient gasket 25 having the extending flange
portion 26 is provided forvsealing the ceramic in
It is believed obviousthat the form of the
electrode 45 may be -varied to a considerable de
gree without departing from the underlying prin
I. ciple'of providing an increased contact area
»between the retained body of mercury and the
engaged face of the electrode. An electrode of
the type such as shown at 22 may, for example,
be provided with a polygonal recess 2| cut into
the face thereof at a point disposed adjacent'the
retained body of mercury 33, so thata portion
40 of this mercury is capable of entering the groove
to increase the contact area of mercury with
the metal of the electrode.
Considering now in detail the structure shown
in Figures 4, 5 and 6, I provide a metal envelope
having the square section 58, having the normally
extending annular shoulder portion 52 and the
enlarged cylindrical portion 53 within which is
disposed a ceramic insert 54 having a square
opening therein indicated at 55 which extends
60 substantially >flush with lthe level of the ñoor
surface of the envelope 50 upon which the body
of mercury 56 is disposed. The ceramic 54 is
provided with an annular ñange portion 51 which
receives the electrode 58, this electrode having a
square head portion of reduced size indicated atV
59 and shown in detail in Figure 5.
A resilient gasket 68 having the short skirt por
tion 62 engaging about the annular ñange 51
is pressed into position by the compression washer
63 which is urged inwardly against the rear face
of the gasket‘68. This seals the ceramic 54 with
lrespect to the internal surface of the shell 53,
'- and also seals the electrode 58 with respect to the
flange 51 to provide a relatively long leakage
65 path between the electrode 58 and the interior
surface of the shell portion 53.
The reduced portion 59 of the electrode 58 is
provided with curved surfaces 64 which are in
the "form of meniscus curves, land provides for
70 full surface contact ofthe advancing straight edge
A suitable contact lug retaining washer indi
cated at 65 in Figure 6V is provided for disposition
against the outer face of the compression washer
63, and is held in position- by the compression ring
66 formed of metal or the like, which is held in Ul
position by the spun-over end 61 of the portion
53 of the metal envelope. The- contact lug re
taining washer 65 is provided with a struck out
tongue portion 68, which has a pair of curved
formable ñnger portions 69 adapted to receive and
engage the end of a conductor lead 10. A spacing
bushing 12 is disposed within the opening 13
formed in the member 65, and 'serves to space a
second insulating washer -member 14- from the
spun-over end of the envelope, in order to in
sulate the lead 18 from the other conductor lead
15 which is connected to a suitable lug 16 carried
by the stud portion 11 of the electrode 58, the
lug 16 being held in position by the clamping
' nut 18.
In the embodiment of the invention disclosed,
the leads 10 and 15 come out from opposite sides
of the switch, but it is obvious that, due to the
provision of the insulating washer 14, the leads
10 and 15 can both come out at the same point in
the periphery of the switch, if desired.
The metallic switch envelope is venclosed in a
suitable moldedphenol condensation product cas
ing 88 which is molded to form and ñts rather
snugly over the portion 50 of the envelope, and the 30
portion 53 thereof, extending to a point disposed ’
approximately in the` plane of the insulating
washer 14. An end cap or mating closure mem
ber 82 is provided which extends over the end
of the stud 11 and encloses the contact lug 16
having a tongue and groove engagement indi
cated at 83 with respect to the portion 80 of the
enclosing casing, whereby the two casings may
be cemented together. Each of the casings is
provided with corresponding openings 84 and 85, 40
which serve as lead outs for the conductors ‘lli
and 15, respectively. It is obvious that if the
two conductor leads are toA be led out from the
same portion of the casing, the closure member 82
will be rotated 180 degrees from the -position
shown in Figure 4, whereupon the opening 85 will 45
be aligned with the opening 84 and the conductors
10 and 15 will be led out from the same side
of the casing, being spaced by the insulating
washer member 14.
The operation of the switch shown in Figure 4 50
is similar to that shown in the other figures, ex
cept that a mercury to metal contact is provided
instead of the mercury to mercury contact pro
vided in the previous switch embodiment. It is,
of course, obvious that the vinsulating enclosing
cover formed by the members 80 and 82 can be -
equally well applied to the switches shown in
Figures 1 and 2, and will function in the same
manner with respect to these switches as de
scribed in connection with Figure 4. In such
cases, the contact lug retaining washer 65 and
the insulating bushing 12 will be applied vto the
stud in order to provide for connection of the cor.
ductors thereto.
Considering now in detail Figure 8, I have dis
closed in this ilgure a switch member 98, pro
vided with the insulating molded cover compris
ing the two sections 92 and 93 corresponding to
the members an and a2 of Figure 4, n1 this em 10
of the body of mercury 56 along the horizontal , bodiment of the invention,'however, the two con»
portion of the curved surface 64 in order to in~ ductor leads 94 and95 are brought out at the same
sure that the greatest cross sectional area of side of the housing through the aligned openings
mercury will come into contact with the electrode 96. The switch of the disclosure shown in Fig
75 upon closing of the circuit.
ure 8 is provided with a jacket member -91 which 15
fits over the enlarged surface of the metallic en
velope of the switch, the casing 92 being cut
away for this purpose, and provides an annular
space 98 _about >the reduced portion of the switch
3. A mercury switch comprising a square metal .
envelope having an enlarged cylindrical end por
tionvjoined thereto by a frusta-conical section, a
ceramic insert in said enlarged portion having a
envelope, which portion 98 is adapted to containV - frusto-pyramidal recess extending axially there
a cooling liquid, such as water or _the like, in
of, a disc-shaped electrode closing the small
troduced through the conduit 99 and exhausted end of said recess and spaced therefrom to define
through _the outlet |00 whereby this water may~ therewith a peripheral rectangular groove, a body
circulate over the reduced portion of the switch of vmercury retained in the lower side of said
90 in order to dissipate heat therefrom. `
groove and having the meniscus thereof project
‘ It is therefore believed that I have provided ing above the edge of said recess for the full
a switch construction which is capable of making - width of the small end of said recess, and a sec
' and breaking currents of considerably greater
capacity than in any previously designed switch
15 of this type and which is capable of operating with
a minimum of heating, since the contact area is
increased to an extent such that a considerably
greater cross sectional area of mercury comes.
into simultaneous contact upon making of the
20 circuit, as compared to the point-to-point con
tact ordinarily produced by rounded or curved
Also, by the use of a ceramic refractory which
is heat conductive, and which has good thermal
25 contact with the metal envelope, I prevent any
localized overheating of any portion of the switch,
since the 'ceramic will conduct away the heat of
localized arcs to the vswitch envelope. Other
ond body of mercury in contact with said envel
ope and movable along the lower side of said
recess into and out of contact engagement with 15
said first body of mercury.
4. A mercury switch comprising a square
metallic envelope having an enlarged cylindrical
end, a thermally conductive refractory in said end
in thermal contact with the interior of said en 20
larged end, an axially extending flange on the
outer end of said refractory spaced radially in
wardly of the end of said envelope, an electrode
supported within said flange, resilient sealing '
means engaging the outer radial face of said 25
flange and electrode and having a peripheral
flange portion disposed between said flange and
the inner surface of said enlarged end of said
features of my invention, such as the relatively l envelope,'a frusto-pyramidal recess in said re
30 long leakage path between the 'electrode and the
metal shell, and the disposition of the ceramic
in the shell in such manner that the sealing means
applies only compressive stresses thereto, and no
internal stresses upon the ceramic are set up,
35 are believed to provide a switch having greatly
improved operating characteristics.
While I am aware that various changes may be
_ made both in the arrangement of parts and
design of the structure disclosed, I- do not intend
40 to limit myself to the specific details shown and
described, and my invention is to be understood
fractory having its small end spaced from said 30
electrode by an inwardly opening groove, a body
of mercury retained in said groove and present
ing a contact surface extending parallel to the
face of said electrode, and a body of mercury in
said envelope movable along one surface of said 35
recess andhaving an advancing edge parallel to
the contact surface of said first body of mercury.
5. A switch comprising a metal envelope hav-~
ing an enlarged lopen end portion, a ceramic in
contact with the internal surface of said end por
tion and having an axially extending flange at
as limited only by the spirit and scope of the - the outer end thereof spaced inwardly of said
appended claims.
I claim:
1._ A mercury switch of the class describe _
having a pair of spaced electrodes, one of said
electrodes _having a planar face portion, a recess
having a transversely extending body of mercury
in contact with said one electrode, a body of mer
cury in'contact with said other electrode and
movable normally to said- face portion of said
first electrode and a planar inclined floor leading
from said other electrode to said recess, said last'
named body of mercury being movable along said
ñoor toward said ñrst electrode upon tilting of
said switch with a straight line advancing edge
extending parallel to said face portion and mov
ing intosimultaneous full length contact with
said transversely extendingbody of mercury.
2. A mercury switch of the class described have
ing a cup-shaped metal envelope, a ceramic in
sert and an electrode extending normal to the
axis of said envelope and supported solely by
said insert, a body of mercury in contact with
said envelope, a body of mercury extending par
allel to one face of said electrode in contact
therewith, and a planar runway formed in said
insert between said bodies of mercury and a
recess at one end of said runway retaining said
70 second body of mercury against movement and
in transverse position across the'full width of
said runwayv whereby said bodies of mercury
. make and break contact between parallel faces
surface, av disc-shaped electrode seated within
said flange, and resilient sealing means engaging
the outer radial surface of said electrode and said _
flange and having a peripheral axially extending
flange disposed between the ceramic ñange and
the internal surface of said end portion.
6. A switch comprising a metallic envelope, a
thermally conductive ceramic in ‘one end of said
envelope having thermal contact about its annu
lar peripheralsurface with the internal surface
of said envelope, an electrode supported solely
by said ceramic and insulated thereby from said
envelope, a body of mercury retained in contact
with said electrode, a frusto-pyramidal recess
lin said-ceramic extending outwardly from said
retained body of mercury to the interior of said
envelope, and a body of mercury in said envelope
movable along a deñning surface of said recess 60
into and out of contact with said retained body
of mercury.
7. A switch comprising Va metallic envelope
having an enlarged cylindrical end portion, a
ceramic insert'therein having an axially extend
ing annular ñange spaced radially inwardly of
the interior of said enlarged portion of said enve
lope, an electrode disc seated within said flange
whereby the leakage distance from said disc to
said envelope includes at least' two surfaces of 70
said ñange and the radial distance from said
flange to the interior of said enlarged end of said _
envelope, and resilient sealing means enclosing
extending substantially the full width of said- `the outer face of' said electrode `anddlange and
having a peripheral flange portion disposed be
75 runway.
tween` said ceramic iiange andthe interior of
said envelope.
8. A switch comprising a metallic envelope, a.
trical engagement with ysaid envelopera'n elec
trode carried by said insert and having an axially
projecting stud, a terminal lug on said stud, con
ceramic ein one end of said envelope having ther-¿ ductorîs connected to said washer and said lug, `
5 mal Contact about its peripheral surface with? insulating spacing means on said stud separat- 5_
the interior of said envelope, an electrodejcarriedn ing the ends of said conductors, and atwo-piece
_ by said ceramic and radially insulated j‘jhereby,? ‘moulded housing enclosing said switch and hav
ing adjacent openingsrrin theirY meeting edges for
and resilient‘ïsealing means comprising a disc
like member having a peripheraì iiange disposed? leading out saidconductors.
1,5. 'I'he combination with a metal envelope 10
mercury switch of the class described having a
9. In combination, a switch comprising a pair of conductors connected to the envelope and
`metallic envelope, a disc-shaped electrode dis-I to arrVY electrode carried by and insulated from said
-posed in insulated position in one end of said envelope, of a housing for saidswiteh compris
15*V envelope and extending? transversely across said ing a first moulded part enclosing ogre end and 15
envelope, a planar` insulating runway-ï between the major lateral periphery of the envelope, and
said electrode and the interior surface of said a second ‘moulded part enclosing the other end
envelope, and a body of mercury movable along ' of said envelope andY having keying engagement
said runway upon tilting of the envelope toward at its edge with> said first part, and? individual
openings in each part adjacent the meeting edges 2o è
20 said electrode and having a straight line advanc
thereof whereby said conductors may be 'led out
ing edge extending transversely across said run
way normal toethe’direction of movement of said from said switch in? any desired angular rela
l0 about Ythe radially insulated part V9i said
10. A switchcomprising
a metal envelope hat;
25 ing a ceramicrinsert seated in one end thereof,
16. A contact lug retaining washeg adapted to
be compressed between the spun-over edge of a 25 '
said insert carrying at its outer end are electrode . metal envelope and the ceramic insert in a mer
radially insulated thereby from saldi-envelope,
'cury switch Yof the class described,-r comprising a
resilient sealing means closing the insert end
of said envelope about-said electrode and radially
overlapping said oneí end off said insert, and
means for axially compressing said sealing means
washer-like ring having an integralY radial pro- i
jection provided at its free end with lateral pro
jecting ears, said ears being bent over to form a 3Q;
in position whereby said insert isV entirely under
over toy dispose' the axis of said socket in a plane
conductor socket and said projection being?bent
sulïstantially parallel to the plane oi said washer.
17. In combination, a metallic switch envelope
switch havingf a square envelope section and an ' having a body portion 'andan enlarged end por- 35'
enlarged cylindrical end portion, of ïa ceramic tion defining therebetweenêan annular shoulder,
disposed in said enlarged end; portionî having an a ceramic insert in said end portion having its
axially extending outwardly projecting iiange, an inner end seated against said shoulder to limit
annular shoulder spaced radially inwardly of said inward movementfof said insert, an axially vex
compressive stress. l
11s-The combination, in a metal Venvelc'gie
40 ñange, and a frusto-îoyramidal recess extending
from the inner. end of said ceramic toward said
shoulder and@ having? its small end terminating
radially inwardly of said shoulder andrspaced axi
ally Èinwardly thereof.
i2'.Y A ceramic insert for a mercury switch of
the class described comprising a thermal con
tending ñange on Vthe outer end of- said insert ¿g
spaced radially inwardly of the interior surface
ofE the end portion of said envelope, an axial
bore in said insert terminating at its outer end in
successive "annular shoulders, an îelectrode disc
disposed :within said ñange andseating against 45 i
one of said shoulders to limit inward movement
ductive refractory having an axially extending ~thereof, and resiiient sealing .means having‘a
disc-'shaped portièn engaging the nouter faces of
irusto-pyramidal recess in one end thereof 'ter
minating inwardly ci’ said end in a rectangular said electrode andñange and havinga peripheral
radial groove of a depth and width suchras to flange extending into the annular space jbetween 50
retain a stable body of mercury therein, said said end portion of said envelope'and sai î?ñange
`groove. having the side away'from "said recess ci’ said insert.
defined by the planar face of an electrode Ísup
ported entirely in the .opposite end of îrsaid
i3. In combination, a metal envelcîpe switch oi'
the class described? havingja ceramic insert in
one end thereof, sealing means for the outer end
‘ci said insert, `a compression ring engaged bythe
60 spun' over end of said envelope for pressing said
sealing means against said insert, a contact lug
washer held in position by said ring and ingelec
trical engagement ?with said envelope, anfrelec
trode carried by said insert, a ccnductorîoon
($5 nected to said washer, a conductorgconnected to
said electrode, a spacing insulatorïbetween said
conductors and carried by sacïid electrode, and a
two piece moulded?housing enclosing said switch
18. In combination, a metallic switch envelope
having aîiody portion and an en_îarged end por
tion deñning therebetween an annular -shoulder, 55
a ceramic insert in saidî end portion having its
inner end seatedî against said shoulder to limitl
inward movement of said insert, an axially. ex
tending "iiange on the outer end of said inserti
spaced radially inwardly lof the interior surfacei 30
of the end portion oi said envelope, an axial bore
said insert terminating at its outer end in suc
cessive annular shoulders, an electrode disc dis
posed within said flange and seating against one
of said shoulders to limitï inward movement there- 65
of, resilient sealing means having a disc-shaped
portion engaging the outer faces of said electrode
and ñange and having a peripheral iiange ex
and having an annular joint provided with open- i tending’Y into the annular space between said ene't
70 ings for leading out said conductors radially oi
said joint;
È14g. In combination, a metal envelope mercury
portionîof said envelope and said ñange of said 70
insert, and a relatively rigid insulating ~disc com
pressed against the outer radial face of said
switch having a ceramic insert in ?one endgthere. ' sealing _means to produce axiaigand radial com
of, compression means for holding saidl insert in pression oi said sealing means on said ñange
position including a-terminal lug `easherin elec
and electrode.
19. In combination, a metallic switch envelope
having a body portion and an enlarged end por
projecting radially inwardly beyond the adjacent
` `tion defining therebetween an annular shoulder,
and an axial recess in the face of said electrode
edgeof the lower defining surface of said recess,
a ceramic insert'in said end portion having its
inner end seated against said shoulder to limit
inward movement of said insert, an axially ex
tending ilange on the outer end of said insert
receiving a portion oi said mercury to increase the
area of contact between said mercury and said
22. In combination, a metal envelope switch of
the class described having a ceramic insert in
spaced radially inwardly of the interior surface
of the end portion'of said envelope, an axial bore
one end thereof, sealing means for the outer end
of said insert, a compression ring engaged by the
spun over end of said envelope for pressing said
sealing means against said insert, a contact lug
10 in said insert terminating at its outer endin Asuc
cessive annular shoulders, an electrode disc dis
' posed within said ilange and seating against one
x of said shoulders to limit inward movement there
washer heldin position by said ring and in elec
of, said disc having an axial thickness such that
the outer radial face thereof is coplanar with the
outer end of said ilange, and resilient sealing
means having a disc-shaped portion engaging
the outer faces of said electrode and ilange and
having a peripheral flange extending into the
20 annular space between said end portion of said
envelope and said ñange of said insert.
20, In combination, a metallic switch envelope
trical engagement with said envelope, an elec-'
trode carried by said insert, a conductor con 15
nected to said washer, a conductor connected to
said electrode, and a spacing insulator between
said conductors and carried by said electrode. -
23. In combination, a metal envelope mercury
switch having a ceramic insert in one end there
of, compression means for holding said insert in
position including a terminal lug washer in elec
having a lbody portion of square form and an trical engagement with'said envelope, an elec
enlarged cylindrical' end defining therebetween a trode carried by said insert and having an axially
25 shoulder, a ceramic insert having its inner end projecting stud, a terminal lug on said stud, con 25
seated against said shoulder, a frusto-pyramidal` ductors connected to said washer and said lug,
recess in said insert, means foraligning said in
and spacing means on said stud separating the
sert with said envelope to maintain the defining ends of said conductors.
surfaces of recess in register with the interior
24. In- a metallic envelope type of mercury
80 deilning surfaces of said body portion,- an elec
switch, a ceramic insert having a frusta-pyram
trode supported in said insert at the end of said idal bore extending axially ‘therein and termi
recess removed from said body portion, and ‘a nating at its smaller end in an acutely angled
body of mercury in said body portion _and mov
straight line transverse cutting edge extending
able along the lower deilning surface of said re
the width of said smaller end, a radially out- .
cess with an advancing edge extending normal to wardly extending wall defining said edge, an axial
the direction of movement thereof toward and wall disposed at the outer end of said radial wall
away-from said electrode. ’
ï extending parallel to said edge, a second radially »
21. In a `metallic envelope type of mercury
switch, a ceramic insert havinga frusto-pyram
40 idal 'recess terminating at its small end in a
outwardly extending wall at the opposite end of
said axial wall, and a planar disc-shaped elec
trode seating against said second radial wall and 40
rectangular radially offset groove, an axially ex- , extending parallel to said ilrst radial wall to
tending annular flange on said insert disposed denne Ywith‘said last-named wall and said axiall
radially and axially outwardly of said groovefa wall a rectangular groove extending the full.
disc-shaped electrode seating in said flange and width of the smaller end of said recess.
45 forming'one deilning wall of said groove.' a body
of mercury in the lower side of said groove and '
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