Note: Descriptions are shown in the official language in which they were submitted.
1~3753;Z
The present invention relates to an electromag-
netic relay comprising a magnet core disposed within the
coil bobbin, said core haviny end portions extending sub-
stantially at right angles to the longitudinal axis of the
bobbin, constituting pole shoes provided with coplanar pole
faces projecting from the bobbin, and further comprising
an armature arranged ex-ternally of said bobbin between
the pole shoes of said magnet core and pivotally supported
along one of its centroidal axes with said pivotal axis
extending perpendicularly to the longitudinal axis of
the coil.
A relay of this general construction is described,
for example, in the German Patent Specification No. 942,406.
In this known relay, the spring rate of the springs serving
to retain the armature is matched to the magnet force/travel-
characteristic curve which is determined by a quadratic func-
tlon in order to improve the responsivity of the relay. If
the contact forces obtained are left out of consideration, it
is possible to reduce the required actuating power to any de-
; 20~ sired extent by reducing the effPctive length of said springs,but this measure tends to reduce the contact forces which may
be obtained. In other words, where it is desired to obtain
larger contact forces, it will be necessary to increase the
energizing power correspondingly. However, in such a case it
is impossible to employ the force developed by the permanent
.
3~11\375i3~ ~
magnet fort~le purpose of increasing the contact forces, because
a large proportlon ofthe permanentmagnet force is absorbed by
the springs serving to retain the armature.
It is also an objec~ of the invention to provlde a
relay of the aforeindicated type which is characteriæed by the ::
fact that it affords a high degree of responsivity, that large
contact orces may be obtained, that the arrangement of the
contacts may be varied in a simple manner, that the relay is
of extremely small size, and that its manufacture on a mass~
production basis does not present any problems. ~-
This object is attained, according to the invention,
by the provision of an electromagnetic relay comprising within
its coil bobbin a magnet core, the ends of which extend sub- .
stantially at right angles to the longitudinal axis of the bobbin
so as to form pole shoes pro;ecting from said coil bobbin and
having mutually aligned pole faces and further comprising an ~ ~ :
armature which is disposed externally of said coil bobbin between
said pole shoes of said magnet core and ~hich is pivotally mounted
for rotation about one of its centroid a~ses, said one axis
extending perpendicularly to the longitudinal axis of said ~
bobbin and parallel to the direction of pro~ection of the pole - ` :
shoes, wherein contact terminals disposed on both sides of the
longitudinal axis of said coil bobbin are positively located
by being embedded in a contact carrier means, said coil bobbin
and the contact carrier means extending substantially over the -~
entire length of the coil bobbin being provided with engaging
means for the mutual positioning and retaining of said contact
carrier means and said coil bobbin, said contact terminals
having associated therewith prelocated contact springs arranged
within said relay, the forces exerted by said contact springs
interacting through sald armature, and bearing means for said
~ :
A` `
i~3753Z
armature provided substantlally centrally of said coil bobbin
between said pole shoes.
A relay of compact construction is thereby obtained
in which it is possible in a simple manner to introduce into
the coil bobbin from one side thereof the contact carriers
provided with their associated contaLts, and the armature
cooperating with such contacts. The fact that all of the
contacts belonging to a given set of contacts are supported
by a common contact carrier obviates any necessity of adjusting
the contact gaps. Contact springs extend~ng along the armature ~
make it possible, in cases in which a magnetically poled relay ~ -
is concerned, to store part of the force of the permanent
magnee, this feature making it possible to provide a relay
which combines a particularly great responsivity with the
availability of large contact forces.
Further advantages achieved by the invention and its
various developments reside in the fact ~hat the various elements
of the relay are combined to a small number of major structural
units, i.e. particularly the coil bobbin with winding and mag-
net core, the contact carrier arrangement with the set of con- ;
-
..
- 2a - ~
~ .
. . .
~375;3'~
tact springs and contact terminals, the arma~ure with contact
actuating members, and these structural units are formed for
positive mutual engagement so that they are easy to assemble
and are automatically placed in the correct spatial relation
with respect to each other. It is a further advantage that
the contact forces may be selected and adjusted within wide
limits. The pivotal mounting o~ the armature is designed in ~ ;
such a way that in spite of the relay being easy to assemble,
a given small play is maintained for the bearing and that the
mobility of the armature is ensured irrespective of the
position of the relay even in case outer forces are exerted
on the closed relay. The precision of the armature bearing
that may be obtained in accordance with the invention results
in a particularly high uniformity of the switching character-
istics and a long service life. Further preferred embodi-
ments provide a relay which may be herlmetically closed on
all sides. It is another advantage brought about by the
formation of the armature and the arrangement of the
contacts in accordance with the invention that a plurality
of simultaneously actuable contacts may be provided selec-
tively as normally open or normally closed contacts.
In order that the invention may be more fully
understood preferred embodiments of it will be described in
the following with reference to the accompanying drawings,
in which:
Fig. 1 is an exploded perspective view of an
embodiment of a relay;
Fig. 2 is a plan view of a completely assembled ~
relay comprising four norm~lly open contacts; ;
Fig. 3 is a part-sectional side view of the relay
,
, .... .. .
. , . ~ , . .. . . . . .
~L037~3~
of Fig. 2;
Fig. 4 is a plan view of a completely assembled
relay comprising two normally closed and two normally open
contacts;
Figures 5, 6 and 7 plan views of further completely
assembled relays respectively comprising two normally open
and two normally closed contacts or three normally open
contacts and one normally closed contact or four normally
open contacts;
Fig. 8 a part-sectional side view of the relay
of Fig. 6;
Fig. 9 a transverse cross-section of the relay
of Fig. 5;
Fig. 10 a part-sectional side view o~ a coil
bobbin provided with a magnet core and a coil and enclosed in
a jacket of pla~tic material molded to enclose the assembly
formed by the components mentioned;
Fig. 11 a plan view of the coil bobbin of Fig.
1 0;
Fig. 12 an enlargbd representation of the detail
enclosed in a circle in Fig. 10;
Fig. 13 an enlarged representation of the detail ~ -
enclosed in a circle in Fig. 11;
Fig. 14 an enlarged sectional representation of the
bearing arrangement of the actuator of the relay of Fig. ~;
Fig. lS an enlarged fragmentary cross section
illustrating the welded connection between a contact carrier
and a baseplate-like bottor~ portion;
Fig. 16 an enlarged representation of the detail
enclosed in a circle in Fig. 8, such detail illustrating one
-- 4 --
.. . .
.
9~V37532
end of an adjusting spring which is provided with longitudinal
slots;
Figures 17, 1~, Figures 19, 20, Figures 21, 22 and
Figures 23, 24 respectively illustrate in graphic representa-
tions the forces occu~ring in the polarized relays which
are respectively illustrated in Fig. 5, Fig. 7, Fig. 4 and
Fig. 2;
Fig~ 25 is an exploded view similar to the lower
portion of Fig. 1 and showing a further embodiment of the
relay according to the invention;
Fig. 26 is a ~lan view of the contact carrier shown
in Fig. 25 with the contact spring mounted;
Fig. 27 is again an exploded view similar to Fig.
1 and showing another embodiment of the relay according to
the invention in which the contact carriers are formed as a
unitary frame;
Fig. 28 shows the two contact carriers prior to
their common encasing to form the contact earrier frame of
Fig. 27; and
2~ Figs. 29 to 31 are three sections in mutually ver-
tieal planes showing a further embodiment of the eleetro-
magnetie relay in accordance with the invention.
The relay shown in Fig. 1 comprises a single-piece
coil bobbin 1 which is provided with a groove 46 adapted to
receive an essentially U-shaped magnet core 2. Prior to the
application of the coil 48 to the bobbin 1, the magnet core
2 inserted in the groove 46 is covered with a small plate
47 of insulating material in order eleetrieally to insulate
the magnet eore frorn the coil. The terminal flanges 35 of
0 eoil bobbin 1 are provided with recesses 6 for the reception
- 5 -
~(~137S3Z
of contact carriers 7 in which contact terminals 8 are fixedlylocated by being embedded therein. The two contact carriers
7 are insertable into coil bobbin 1 in such a manner as to
be sy~netrically arranged in relation to the lon~itudinal
axis of the bobbin, and each contact carrier is provided
with two separate switching contacts eachof which is formed
by a contact spring 12 attached to one oE two portions 11 of
said contact~carrier and by one of the contact-material bear-
ing portions 10 of one of the contact terminals embedded in
1~ the respective end portion of the contact carrier. With the
contact carrier 7 in position in bobbin 1, the contact ter-
minals ~ are aligned with the coil terminals 49, the spacing
of the various terminals corresponding to a conventional
pattern. As regards the terminals 8 and 49, such terminals
may be arranged in accordance with the well-known dual-in-
line system. After the preassembled contact carriers 7 have
been inserted into bobbin 1, a bearing plate 25 made of a
plastic material and centrally provided with an integrally
formed pivot pin 22 for armature 5 is inserted into bobbin
1 and fixedly located at its end faces ~6 by the pole shoes
3 of magnet core 2. For the purpose of locating bearing
plate 25, this plate is provided at its ends interrnediate
its longitudinal edges with recesses 27 matching the profile
of pole shoes 3. This method of locating pivot pin 22 in
relation to pole shoes 3 ensures maxim~n accuracy as regards
the bearing arrangement for armature 5. The length of
pivot pin 22 is selected in such a manner that it exceeds by
an amount defining a vertical end play of the bearing the
depth of a through bearing hole 9 with which armature 5 is
provided. The said bearing hole 9 is formed in a plastic
-- 6 --
~037532
formation 20 disposed intermediate -the ends of armature 5.
Upon the relay being enclosed in its housing can 23, the
end face 24 of pivot pin 22 will bear against the inner
surface of the upper wall of housing can 23. This arrange-
ment ensures that the mobility of armature 5 will be
maintained even in cases in which housing can 23 is subjected
to pressure. Bearing plate ~5, while serving to support arm-
ature 5 for rotation, also serves to locate the two contact
carriers 7. To permit this, contact carriers 7 are provided
with stepped recesses 28 which are engaged by the under side
of bearing plate 25. The armature 5 which is supported for
rotation between the two pole shoes 3 on pivot pin 22 is
provided with plastic formations 19 and 20 each of which
encloses a predetermined part of the armature; in such plastic
formations there are provided two elongated ferromagnetic
portions 43 of the armature, such portions being disposed on
: opposite sides of bearing hole 9. Two permanent magnets 44
are disposed between the two portions 43 of armature 5 on
opposite sides o~ bearing hole 9 to extend between said ~- .
20 plastic formations 19 and 20. The ferromagnetic portions 43 ;
extend parallel to one another and their length is selected ~ .
in such a manner that, when in position in the relay, .
: their end portions straddle the adjacent end portions of
the pole shoes 3 of magnet core 2. A polarized relay pro-
vided with an armature 5 of the type just described is operable ~ :
as a bistable switching devlce because the equally
long end portions of ferromagnetic portions 43 overlap effective
pole faces 4 of equal size on the pole shoes 3 of magnet
core 2. Thus, the attractive forces produced by the perman-
ent magnets 44 inserted in the armature 5 will cause the
- 7 ~ ~ :
", ' ' ,~,' ,., '" ',-, . ','' - ~ ,"',
~L0375i3~
actuator to remain in the respective last switching position
- into which it was brouyht by energization of the relay, it
not being necessary to continue the supply of electric ener-
gy. The contact springs 1~ are operated by lugs 21 with
which the plastic formations 19 surrounding parts of the
armature are provided. In the arrangement shown, the adjus-
ting springs 13 may also act on armature 5 through bearing
surfaces 50 provided on the armature. As shown in Fig. 1,
it is possible to substitute for the above-described armature
5 a modified armature 5' which is again provided with plastic
formations 19 and 2~ and which includes ferromagnetic portions
45 of equal length extending parallel to one another on
opposite sides of the armature bearing hole 9 but longitudinally
offset in relation to one another in such a manner that,
depending on the switching position of the armature
differently sized portions of the pole faces 4 of pole shoes
3 will come into efEect. The armature 5', in similarity
to the armature 5, is also provided with permanent magnets
which are inserted in such a manner that the bar-like
portions are in contact with magnet poles of identical polarity.
A reIay provided with an armature 5' of the type just described
will be operable as a monostable switching device because,
depending on the switching position assumed by the actuator,
differently sized effective portions of the pole faces are
brought into action. In this case, the stable switching
position of the actuator will be determined by the larger
of the two pole faces 4 which comes into action. It has
already been proposed to store the force produced by the
permanent magnets in the contact springs by exerting a
force on the contact springs. In such an arrangement, the
- 8 -
~L~137~3~ ~
, . . .
contacts will have to be opened by the ~heren-t force of the
contact springs. However, in cases in which the relay was
energized by an excessivel~ strong current in order to close
the respective contacts, the contacts may adhere to one
another as a result of a slight welding action so that the
spring force will no longer be sufficient to Gpen the contacts.
In the embodiments of the invention just described, this risk
is avoided almost completely in view of the fact that the ~ , -
contacts are reopened against the bias of the contact springs
by the entire force produced by the system of magnets.
Figures 2, 3 and 4 illustrate relays of the general
type shown in Fig. 1. In such relays, the pre-assembled
contact carriers 7 have been inserted into the bobbin 1,
and the armature bearing plate 25 and the armature 5 have
been placed in position. As will be seen in Fig. 3, the -~
base of pivot pin 22 is surrounded by an annular bead 52
serving to establish a predetermined air gap 53 between bearing `-
plate 25 and armature 5. The relay is enclosed in a housing ;~
can 23 which is closed at its bottom by a base plate 40. As
20 will be seen in Figures 2 and 4, housing can 23 is formed ;
~... ~ ... .
with internal rib-like projections 41 which extend between
the upper lugs 11 of contact terminals 8 projecting from
contact carriers 7 and which bear against said contact
carriers 7 and armature bearing plate 25 which latter `~
members act as fixed abutments. This arrangement serves -~ -
to increase the rigidity o~ housing can 23 and to maintain
., ,
the play of the bearing supporting the armature 5 even in `
cases in which the entire relay is subjected to large
mechanical loads; in addition, this arrangement tends to ;~
increase the dielectric strength between the lugs 11 of
_ g _
~' ':
:. ,. :,: ,: , . . .
~al375i3Z
contact terminals 8 which are separated by said rib-like pro-
jec tions of the housing can.
The relays shown in Figures 2 to 4 are constructed
as polarized bistable relays which are provided with an H-
shaped armature 5 of the type shown in Fig. 1. More in
particular, the relay of Fig. 2 includes four normally open
contacts. In view of this fact, there have been substituted
for two of the afore-described lugs 21 two diametrically
opposed bearing surfaces 51 on the ends of armature 5, such
bearing surfaces being adapted to cooperate with actuating
members 14. Each actuating member 14 is attached to the free
end of an associated adjusting spring 13 and is arranged
to extend through an aperture formed in the associated contact
spring 12. With the relay of Fig. 2 in the position shown,
all of the four contacts are open. Those contacts with
which the corresponding actuating member 14 extends through
the aperture 15 of the associated contact spring 12 are held
in their open positions because the force of the adjusting
spring 13 exceeds the force of contact spring 12. The
remainlng contact springs 12 have been operated by the lugs
21 of armature 5 which have lifted the contact springs from
the portions 10 serving as fixed contacts. Figures 23
and 24 illustrate for the case of the relay of Fig. 2 the
pattern of the forces occurring in the relay as a function
of armature travel s. Said armature travel s is plotted
on the abscissa, the forces being plotted in the ordinate
direction. The switching position shown in Fig. 2 corresponds
to pOill t b in Figures 23 and 24. The contact spring forces
acting on armature 5 are indicated as 2P2, the adjusting
spring force opposing such forces being indicated as Pl.
With armature 5 assuming its centered position 0 as shown
-- 10 --
: . .. ..
1~3~53Z
in Figures 23 and 24, the forces Pl and 2P2 are of egual
magnitude and will cancel one another. The differential force
exerted by the springs is designated as P3 and plotted in
the lower part of Fig. 24. As armature 5 moves further
towards its position a, the preloaded contact springs 12
will abut the portions 10 of contact terminals 8 serving as
fixed contacts, the respective contact forces acting on such
contacts being indicated in Fig. 24 as P4 and P5. In any
case, the forces applied by contact springs 12 on armature 5 will
lo be removed at the moment at which the contacts are closed. After
the contacts are closed, the armature S which, according to
Fig. 24, is operated by the permanent magnet force P which
increases approximately quadratically as a function of its
de~leetion will exclusively have to overeome the force Pl
exerted by the adjusting springs That portion P6 of the
adjusting spring force Pl which with the arm~ture in its
switching position a exeeeds the sum oE the contact forces
P4 and P5 will be derived from the permanent magnet force
and stored in adjusting spring 13. Therefore, when the
~0 relay is to be re-energized, it will be necessary to supply
only that amount of electric energy which is sufficient to
supply the difference between the permanent magnet force Pm
and the sum of the stored spring forces P4 ~ P5 ~ P6.
The relay shown in Fig. 4 comprises two normally
open contacts and two normally closed contacts. The contact
springs 12 are operated by lugs 21 of the plastic formations
19 on armature 5, whereas the adjusting springs 13 are
operated by bearing surfaces 50 formed on said lugs. The
pattern of the forces occurring in the relay of Fig. 4 as a
3 ~ function of armature travel s is shown in Figures 21 and 22.
The switching position shown in Fig. 4 corresponds to point b
.
~3753Z
in Figures 21 and 22. The forces exerted on armature 5 from
one side thereof by adjusting spring 13 and contact spring 12
act in the same direction. However, the adjusting spring
forces Pl and Pl' as well as the contact spring forces P2 and
P2' applied to the armature from opposite sides thereof act
in opposite directions. The various spring forces acting on
armature S produce a resultant force P3 which becomes 2ero
with the armature assuming its centered position. With arma-
ture 5 in its centered position, the magnetic force P opposing
said resultant spring force will also be zero but will in-
crease approximately quadratically beyand this centered posi-
tion. In Figures 21 and 22 the contact foxces capable of
being produced by the preloading of contact springs 12 are
shown at P4 and PS.
With armature 5 assuming,one of its terminal posi-
tions a and b, the armature will still be acted upon by forces
P6' and P6" which are respectively app;Lied by two oppositely
arranged adjusting springs 13. The forces P6' and P6" of
said adjusting springs 13 and the force P4 of one of contact
springs 12 oppose the magnet force Pm so that for the purpose
of energizing the relay it will be necessary to supply such
an amount of electric energy only as will be required to pro
duce a corresponding differential force. It will, therefore,
be seen that also the relay of Fig. 4 is characterized by
a particularly small energy requirement which, however, can-
not be reduced indefinitely because such factors as external
influences such as shocks or vibrations, and unavoidable
manufacturing tolerances have bo be taken into consideration.
Figures 5 to 16 illustrate embodiments of relays
0 according to the invention in which the bobbin 1 in which the
~ 12 -
~.
~ ~037532 ; :~
magnet core 2 i5 received is provided wi-th an injection-molded
jacket of thermoplastic material carrying an integrally formed
pivot pin designed to support the pivotally mounted armature
5. As particularly shown in Figures 8 and 14, armature 5 is
provided intermediate its ends with a blind hole 29 in which
pivot pin 22 is received. The operation of forming said
blind hole 29 presents no manufacturing problems in vlew of
the fact that this hole is formed in the plastic formation -
20 surrounding a central portion of the armature. The free ~ ~ -
10 end of pivot pin 22 forms a part-spherical surface 30, this ` ~-
surface bearing against the bottom 31 of the blind hole.
The depth of blind hole 29 is selected to be smaller than ~-~
,
the free length of pivot pin 22 so that a small air gap 53 ~ `
~ .
remains between the injection-molded enclosure 54 of plastic
material and the plastic formation 20 with which armature 5
:: ~. . .
is provided. Thus armature S is supported for rotation in
such a manner that the frictional forces opposing rotation of
the armature are kept at a minimum. In order to prevent
armature 5 from being disengaged from pivot pin 22, said ~;
.... .
armature is provided on its upper surface 32 with a conical -~
projection 33 whose height is selected in such a manner that,
wlth housing can 23 in position, there will remain a narrow
air gap 3~4 between such projection 33 and the adjacent inner ; ~
surface of housing can 23. The width of air gap 34 is ~ ;
determined by the magnitude of unavoidable tolerances -
regarding the flatness of the upper wall of housing can 23.
Since air gap 34 is extremely narrow, the relay may be
installed in any desired orientation. As shown in Figures
5, 6, 7 and 9, housing can 23 is provided with internal ~-
rib-like projections 41 serving to enhance the rigidity of
- 13 ~
. . .. . .
11:);~753~
the housiny can and adapted to bear against stationary
abutment 42 provided, for example, on the plastic enclosure
54 of coil 48. With this arrangement, the freedom of armature
5 will be maintained even in cases in which the relay is
subjected to mechanicai loads, for example by pressure being
exerted on housing can 23. During the operation of injection-
molding the enclosure 54 surrounding bobbin 1, there will
simultaneously be molded a baseplate-like bottom portion 37 '
as shown in FigureslO and 11 between the recesses 6 for receiving ~'~
the contact carriers 7 indicated by cross-hatching in Fig.
11 and,' in addition, a cavity 56 adapted to receive electrical
circuit elements, said baseplate-like bottom portion 37 being
provided with apertures 38 ~Fig. 11) adapted to receive the
contact terminals 8 extending therethrough. As shown on an
increased scale in Figures 12 and 13, said apertures 38
~ormed in said baseplate-like bottom portion 37 are surrounded
on the side thereof facing the interior of the relày with
rldge-like projections 39 having a triangular cross-sectional ~;
shape. Such projections 39 are adapbed to being used in
welding together said baseplate-like bottom portion 37 and
::
~said contact carxiers 7 with the aid of an ultrasonic ''
welding process or the above-described hot-~late welding
process. As shown in Fig. 15, such welding operation will
cause the material of said rldge-like projections 39 to be~
softened, thus hermetically sealing towards the exterior of
; the relay the contact terminal 8 which is embedded in contact
carrier 7 and which extends with~ a predetermined clearance
thro'ugh its associated aperture 38. The height of each pro-
jection 39 is selected in such'a manner that there will re~
30 main a narrow air gap 55 after contact carrier 7 has been ~'
'
.,
.,
welded to said baseplate-l~ke bottom portion 37. In the
arrangement shown, air yap 55 serves to compensate for un-
avoidable manufacturing tolerances to be expected in contact
carrier 7 and/or bottom portion 37.
The relays shown in Figures 5 to 8 comprise adjus-
ting springs 13 ~hich are provided at each of their free ends
with two slots 16 extending longitudinally of such springs. -
In this arrangement, the forces produced by *he end portions
17~ 17' of the adjusting springs separated by said slots 16
are respectively transmitted to contact spring 12 and the
plastic ~ormation 19l. Fig. 16 is an enlarged fragmentary
view of such a slotted end of an adjusting spring 13. The
end portions L7' exert forces on the adjacent contact
spring 12, thus increasing the contact force during contact
closure, whereas the central end portion 17 of adjusting
spring 13 bears against armature 5, thus increasing the
,amount of permanent magnet force capable of being stored.
.
The forces coming into play during a switching operation in the
relays shown in Figures 5 and 7, respectively, will be
~20 explained in more detail in the following paragraph.
~` ~ The relay of Fig. 5 is provided with two normally
closed contacts and two normally open contacts; in Fig. 5
.
the armature 5 of the relay is shown in its centered position~
The pattern of the spring forces and of the attractive force
exerted by the permanent magnets is shown in Figures 17 and 18.
The forces exerted on one side of armature 5, iOe. the force
P2 applied by contact spring 12 and the force Pl applied by
adjusting spring 13, act in the same direction but in opposition
to the forces which are applied to the opposite side of arma-
ture 5 by the respective contact and adjusting springs, such
- 15 -
, . . . . . . .
~3753Z
forces being respectively designated P2' and Pl'. The re-
sultant P3 of all spring forces acting on armature 5 is shown
in Fig. 18. ~ith the armature assuming its centered position
corresponding to point 0, the resultant force is zero. As
compared to the contact forces occurring in the relay of Fig.
4, the contact forces P4 and P5 capable of being obtained in
the relay of Fig. S are respectively increased by -the force
Pl or Pl' exerted by the respective adjusting spring 13.
Due to the fact that upon a contact being closed the end
portions 17' of adjusting spring 13 are brought into contact
with contact spring 12 results in an increase in the current
carrying capacity of the respective contact. This effect is
to be attributed ~n the one hand to an increase in contact
force resulting in a reduction in contact resistance and
on the other hand to the fact that the adjusting spring
will itself act as a current carrying member.
The relay shown in Fig. 7 resembles the relay shown
in Fig. 2 in that it is also provided with four normally open
contacts. The pattern of the forces occurring in t~is relay,
such forces being a function of actuator deflection s, is
shown in Figures 19 and 20. With all contacts being fully
opened, the position of the relay corresponds to point b in
Fig. l9; when one half only of the contacts of the relay is ;~
considered, two contact springs 12 apply a force 2P2 on arma- -
ture 5, and one adjusting spring 13 applies thereto a force Pl.
These forces 2P2 -~ Pl are bpposed by the force Pl applied by
the upper adjusting sp~ing 13 shown in Fig. 7. The resulting
force P3 is shown in Fig. 20 to become zero as armature 5
approximately assumes its centered position. This resulting
force opposes the quadratically varying force P produced by
- 16 ~
. : . , . , ~ : :. . : . . ;
~ ~753Z `
the permanent magnets. Also in this case, the fact that the
two end portions 17' o~ adjusting spring 13 come into action
results in an increase in contact force, this, however, apply-
ing only to the lower normally open conta~t of that hal~ of
the relay o~ Fig. 7 which is here being considered. Thus,
the contact force P5 as compared to the contact fiorce avail-
able in the relay of Fig. 2 is increased by the force exer-
ted by the adjusting spring, whereas the contact force P4
occurring at the other contact will assume the same value as
in the case of the relay of Fig. 2.
The embodiment shown in Figs. 25 and 26 differs from
that of Fig. 1 in the way the contact carriers 7 and contact ~`~
springs 12 are ~ormed while the remain:ing elements, particu-
larly armature 5, bearing plate 25, base plate ~0 and housing
can 23 are identical. In the embodiment of ~igs. 25 and 26,
three contact terminals 8 are embedded in the contact carrier
7', the outer two of the contact terminals 8 being connected
with the portions 10 forming the ~ixed contacts, while the
middle~contact terminal 8 is connected to a common lug 11'
~carr~ing a common contact spring 12'. The middle lug ll'
is divided by two cuts lle and llf into three upwardly
extending smaller lugs lla, llb and lld with the lug lld being
substantially disposed in the plane o~ the portions 10. The
lug lld carries on its surface opposite from the coil bobbln
1 a projection llc onto which contact spring 12' may be
mounted with a corresponding central hole 12c. The contact
spring 12' is provided with a movable contact 12a, 12b at
each end. When assembled, the movable contacts 12a, 12b
areSopposite to the portions 10. Between the movable
contacts 12a, 12b and the middle hole 12c, the contact spring
- 17 -
~37S3Z
12' is furthermore provided with two tongues 12d and 12e
which are cut out along three sides and are bent to the side
opposite to that of the movable contacts. As shown in
Fig. 26, the free ends of the tongues 12d, 12e in the
assembled condition abut the inner surfaces of the lugs lla
and llb, respectively, thereby increasing the force of the
contact spring. By correspondingly setting the tongues 12d,
12e, the contact pressure may be finely adjusted.
The embodiment shown in Fig. 27 differs from that
of Fig. 1 in the shape of the coil bobbin and the contact
carrier. While in Fig. 1 the coil bobbin 1 constitutes the
basic element and one contact carrier is inserked into
corresponding recesses 6 provided on each side of the coil
bobbin, the two contact carriers in the embodiment of Fig. 27
are in the form of an integral frame 57 into which the coil
bobbin 1' is inserted. In this case the frame 57 thus forms
the supporting element of the entire relay. The frame 57 has
a closed lower s~e penetrated by the contact terminals 8.
In thè embodiment of Fig. 27 as in that of Fig. 1, the magnet
core is disposed within the coil body 1' with its two pole
shoes 3' extending upwardly out of the coil bobbin. However,
the~pole shoes 3' are provided with outwardly stepped portions
59 extending beyond the coil bobbin 1' in the longitudinal
directionu When assembled, the stepped portions 59 engage
correspondingly shaped central recesses 58 provided at the
inner side of the end walls of frame 57. In this way the
coil bobbin is positioned accurately within the frame.
Lateral connecting portions 60 are also provided on the end
walls of frame 57 and are connected to coil terminals 49
extending downwardly from the frame 57. When inserting the
- 18 -
... . . . .
1037~;i3;2
coil bobbin 1' into the frame 57, the terminals 61 forming
the ends of coil 48 engage the connecting portions 60 and
are soldered or welded thereto.
Fig. 28 shows the two CQntact carriers 7" which
form the two main parts of frame 57. The contact carriers
7" into which the contact terminals 8 and coil terminals 49
are embedded consist of thermosetting plastic and are ~-
encased by injection molded thermoplast to form the frame 57
shown in Fig. 27 in its completP form. The molded encasing
forms an upper edge 62 which in the assembled condition
of the relay engages the lower edge of the housing can 23.
As a final step in the assembly o~ the ~lay, the housing
can 23 is welded to the thermoplast encasing of the frame 57.
The entire relay is thus provided with a hermetically tight
encasing only penetrated at its lower side by the terminals.
In the embodiment represented in Figs. 29 to 31,
similarly as in ~igs. 27 ~nd 28, two contact carriers 7'''
form an integral frame into which the coil bobbin l' including
the magnet core 2 is inserted. As particularly understood
20 ~from Fig. 29, the coil bobbin 1' consists of two flat parts ~~~
of general I shape disposed on both sides of the magnet core
2 and retained together with the core by the coil 48 to form
a unitary structural ~lement. The two contact carriers 7''' ~`
are directly supported by the two ends of the magneti~ ~ore
extending from the coil bobbin l' and are welded together
at their surfaces facing each other below the coil 4a and
outside the magnet core 2. A welding seam is shown at 70 in ~ ``
Fig. 29. To facilitate the assembly and positioning of the
two bobbin parts, one of them has a stud 71 engaging a
corresponding hole in the other part. The armature 5' is
-- 19 --
~ 1e~3~32
similarly as in the embodiments of Figs. 5 to 8 partially
embedded in plastic formations 19' and 20' with the middle
formation 20' having in its center two coaxial bearing pins -
63 extending upwardly and downwardly. The bearing pins 63 ' ,~
engage corresponding bearing sleeves 64 integrally formed - -
~: .
on a lower bearing plate 65 and an upper bearing plate 66. ;
The two bearing plates 65 and 66 are interconnected by '~
straps 67 so as to form a cage pivotally mounting in its
interior the armature S'. The bearing plates 65 and 66 are ~ ~
10 provided at their outermost ends with cut-outs embracing ' ~ -
the pole shoes 3 of the magnet core 2. The armature 5' is '~
thus positioned in fixed spatial relationship to the magnet
core 2.
For increasing the breakdown voltage between, the
various contacts, the housing can isprovided similarly as in
the embodiment of Figs. 5 to 8 with inner rib-like projections
41. Furthermore, the housing can 23 is formed of transpar~nt ,`
plastics material; as shown in Fig. 30, it has integral lense ,~
portions 68 formed above the contact places and providing
a magnifying effect to facilitate the observation of the
' contact operation. A further difference of the embodiment ,~
of Figs. 29 to 31 with~respect to those described above
resides in the fact that the contact carriers are provided `~
with stepped portions 69 shown in Figs. 29 and 30 from ,~
which the coil terminals 49 project. These stepped portions ''~ ,~
69 provide a greater distance and thus a higher breakdown '`,`~
voltage between the coil terminals and the switching contacts , '~
10 which are at a different potential.
- 20 ~
' ,
