Year: 1898

page_text: [Communicated from abroad by ACTIEN-GESELLSCHAFT MIX & GENEST,- Electrical
Engineers, of 67, Bulow Strasse, Berlin, W., in the German Empire.]
I, HERMANN OPPENHEIMER, Electrical Engineer, of 55, Redcross Street, Barbi-
can, London, E.C., do hereby declare the nature of this invention to be as
follows:-
Annunciator movements hitherto in use in central or multiple switchboards
require a comparatively large space, and labour under the disadvantage of being
badly visible when placed high above the operator's eye.
My invention aims at the remedy of said disadvantages by placing the indicator
disc in a more favourable optical angle in the horizontal elongation of the
electro-magnet causing the disc's appearance.
In Fig. 1, I show such annunciator movement in perpendicular section. In
Fig. 2, the plan, in Fig. 3 the back view, in Fig. 4 the front view, and Fig. 5
shows an alternative construction.
The apparatus as shown in Figs. 1 to 4, consists of an electro-magnet a which
is surrounded by a metal mantle 6. The coil of the electro-magnet is connected
with one end to the line c of subscriber, and with the other end to the earth
return d, in both cases the wire passing through the metal mantle of the
annunciator by means of insulating bushes.
The armature e of the electro-magnet rests with its top part between points
attached to the side arms F of the apparatus, and there is also a spring 9 which
touches the metal mantle b.
The armature has a further extension pièce h, which rests with its free end i
closely on the top of the one end of the number plate k. Such number plate is
angle-shaped, and rests by means of spindle k¹, the bearings of which are the
side arms during the normal position in such a manner that the one shank
which carries the numbers is in a horizontal, or approximately horizontal position
(Fig. 1) being hidden by the screen 7.
The angle-shaped number plate has at the end which faces the extension
piece h, a metal nose 3 which reaches just underneath the extension piece i of
the armature. A counterweight attached to the axis of the number plate
is of such dimension that the lifting of the plate requires only very little power.
As soon as the subscriber rings up, he closes the circuit c, the current passes
through the contact m, the wire of the electro-magnet to earth. The armature e
is attracted, and with its extension piece h acts on the metal nose ³ of the
number plate, lifting this plate into the position as shown by dotted lines (Fig. 1).

page_text: As however, the circuit is only closed temporarily by the calling-up subscriber,
the number plate would soon drop. To prevent this dropping of the number
plate, and to retain it in its position as shown in the dotted lines, thus being
visible to the operator, the armature e has a further extension piece n, which
when the number plate is lifted comes into contact with spring o insulated from
the metal mantle 6. This latter spring is electrically connected to a branch
line going to c.
Besides that, a local battery g is connected to the iron core of the electro-
magnet, which at this point is surrounded by a ring fixed to the mantle b.
As soon as the contact between the extension n and the spring o is made by the
call, part of the current of the local battery goes through the iron core,
the armature, extension n, spring o, the branch line P', line C, contact and
the coil to earth, whereas the other part of the current goes through the ring r,
the metal mantle b, spring g, extension n, spring o, branch line p, line c, con-
tact m, and the coil to earth.
m,
The local circuit thus retains the number plate in the position shown in dotted
lines Fig. 1, into which such plate has been brought in the first instance by
the call.
The shank which carries the number is now easily visible to the operator,
who can ascertain the number without exertion, and as soon as the operator has
ascertained the number, the circuit is interrupted by inserting the plug into
the springjack, and the plate drops as the armature goes back to its normal posi-
tion where it remains until a new call is given.
The spring o not only serves to close the local circuit, but it answers the
further purpose to diminish the pressure on the pivots of the armature, which is
caused by the turning of the armature in consequence of the action of the exten-
sion piece h.
Fig. 5 represents an arrangement whereby the angle-shaped number plate can
be attached to an ordinary annunciator movement.
Dated this Sixth day of April 1898
COMPLETE SPECIFICATION.
Improvements in and connected with Annunciators for Telephone
1
Systems.
I, HERMANN OPPENHEIMER, Electrical Engineer, of 55, Redcross Street, Barbi-
can, in the City of London (communication from abroad from Actien-Gesellschaft
Mix & Genest, Electrical Engineers, of Bulow Strasse, 67, Berlin, W., in the
Empire of Germany), do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
Annunciator movements hitherto in use in central or multiple switchboards
require a comparatively large space, and labour under the disadvantage of being
badly visible when placed high above the operator's eye.
My invention aims at the remedy of said disadvantages by placing the indicator
disc in a
more favourable optical angle in the horizontal elongation of the
electro-magnet causing the disc's appearance.
In Fig. 1, I show such annunciator movement in perpendicular section. In
Fig. 2 the plan, in Fig. 3 the back view, in Fig. 4 the front view, and Fig. 5
shows an alternative construction.

page_text: The apparatus as shown in Fig. 1 to 4, consists of an electro-magnet a which
is surrounded by a metal mantle b. The coil of the electro-magnet is connected
with one end to the line c of the subscriber, and with the other end to the earth
return, in both cases the wire passing through the metal mantle of the
annunciator by means of insulating bushes.
The armature e of the electro-magnet rests with its top part between the
points of the side arms f of the apparatus, and has at this point a spring y which
touches the metal mantle b.
The armature has a further extension piece which rests with its free end i
closely on the top of the one end of the number plate k. Such number plate is
angle-shaped, and rests by means of spindle, the bearings of which are the
side arms during the normal position in such a manner that the one shank k
which carries the numbers is in a horizontal or approximately horizontal position
(Fig. 1) being hidden by the screen 7.
The angle-shaped number plate has at the end which faces the extension
piece h, a metal nose which reaches just underneath the extension piece i of
the armature. A counterweight attached to the axis of the number plate
is of such dimension that the lifting of the plate requires only very little power.
As soon as the subscriber rings up, he closes the circuit c, the current passes
through the contact m, the wire of the electro-magnet to earth. The armature
is attracted, and with its extension piece acts on the metal nose k³ of the
number plate, lifting this plate into the position as shown by dotted lines (Fig. 1).
As however the circuit is only closed temporarily by the calling-up subscriber,
the number plate would soon drop. To prevent this dropping of the number
plate, and to retain it in its position as shown in the dotted lines, thus being
visible to the operator, the armature e has a further extension piece n, which
when the number plate is lifted comes into contact with spring o insulated from
the metal mantle b. This latter spring is electrically connected to a branch
line p going to c.
Besides that, a local battery 9 is connected to the iron core of the electro-
magnet, which at this point is surrounded by a ring fixed to the mantle b
As soon as the contact between the extension and the spring o is made by the
call, part of the current of the local battery, gods through the iron core,
the armature, extension », spring o, branch line 7, line c, contact m, and the
coil to earth, whereas the other part of the current goes through the ring r
the metal mantle b, spring g, extension n, spring o, branch line p, line c, con-
tact m, and the coil to earth.
The local circuit thus retains the number plate in the position as shown in dotted
lines Fig. 1, into which such plate has been brought in the first instance by
the call.
The shank which carries the number is now easily visible to the operator,
who can ascertain the number without exertion, and as soon as the operator has
ascertained the number, the circuit is interrupted by inserting the plug into
the springjack, and the plate drops as the armature goes back to its normal posi-
tion where it remains until a new call is given.
The spring o not only serves to close the local circuit, but serves the
further purpose of diminishing the pressure on the pivots of the armature, which
manifests itself when the armature is turned, in consequence of the influence the
extension piece h exercises on the number plate.
Fig. 5 represents an arrangement whereby the angle-shaped number plate can
be attached to an ordinary annunciator movement.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. An electric annunciator movement in which the spindle of the number

page_text: plate when normal is horizontally arranged outside such plate, in such a manner
that the latter will, after the closing of the ringing up circuit, appear in a
rectangular position towards the vision of the operator, substantially as and
for the purpose specified.
Dated this 2nd day of December 1898
HERMANN OPPENHEIMER.