Improvements in Electric Mechanism for Operating Telephone Call Bells and Annunciators.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Mechanism for Operating Telephone Call
Bells and Annunciators.
I HENRY BIRKBECK of 34 Southampton Buildings Chancery Lane London in the
County of Middlesex Patent Agent (a communication to me from abroad by
Frederick William August Schneider, Machinist of 12 Pearl Street and William
Carl Zeidler Manufacturer of 12 Nelson Street both in the City of Toronto in the
County of York in the Province of Ontario Canada) 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 :-
The object of the invention is to design simple mechanism for operating an auxiliary
telephone call bell and annunciator and it consists essentially of a telephone call bell
and annunciator so connected to the telephonic circuit that upon being signalled its
action breaks the circuit leading to the magnets of the call-bell and switches it onto
a line leading to the magnets of an auxiliary call-bell situated at a point remote from
the telephone.
Figure 1, is an outside view of a telephone showing the door closed to expose the
annunciator.
Figure 2, is a view of the telephone with its door open to expose the signalling
mechanism.
The wires A and B, represent the line of the telephonic circuit; the wire A,
connecting directly with the magnets C, of the telephone call-bell, while the wire B,
connects with the said magnets through the following mechanism, that is to say,
it first connects with the plate D, which is properly insulated. The spring E, which
is connected to the wire F, leading to the magnets C, is held against the plate D
by the pivoted lever G, when the said lever is set in the position indicated, the
connection of the line A-B through the magnets C is complete. To hold this
lever G, in the position shown, a notch is made in the armature H. When the
signal is given from the central station of the telephonic circuit, the magnets C, are
magnetized, and the call-bell I, is actuated in the ordinary manner. The magnetizing
of the magnets C, draws, the armature H, away from the end of the lever G, which
lever, being weighted at its other end, moves back on its pivot so as to leave the
spring E, clear, when the said lever moves clear of the spring E, and thus breaks
the circuit to the magnets C. As the lever G is electrically connected with the
plate D, a circuit is formed when the said lever comes in contact with the pin J,
which is properly insulated and electrically connected with the wire K, which leads
to an auxiliary call-bell situated at a point remote from the telephone. The wire L,
leading from the magnet C, connects with the auxiliary call-bell and thus the circuit
which previously operated the call-bell, F, is connected so as to operate the call-bell
when the signal is next given.
In order to prevent the instantaneous breaking of the circuit through the spring E,
we provide a small cylinder M is provided in which a piston connected to the
lever G, is fitted so as to form an air or oil cushion and prevent the lever falling
away from the spring E, too quickly.
It should be mentioned that when the door N, is closed, the lower end of the lever G,
projects over the lever O.
From this description it will be seen that the first signal from the telephonic circuit
is announced through the call-bell I, and by the time that this first signal is given
the circuit for operating the call-bell I, is broken and a fresh circuit formed through
the auxiliary call-bell, which call-bell would then announce the next signal given
from the other end of the telephonic circuit.
When the lever G falls as before described it rests npon the top of the lever O,
when the said lever is held down by the weight of the receiver P. When the

page_text: receiver P, is taken off the lever O, the said lever springs up in the usual manner,
and acting against the lever G, tilts it upon its pivot so as to bring its and into the
notch made in the armature H, and thus hold it in the position indicated in Figure 2;
the lever G resuming contact with the spring E; consequently the removal of the
receiver P, from off its hook reforms the circuit so that the next signal will act upon
the call-bell I.
As a signal cannot be given twice in succession on the call-bell I, without the
removal of the receiver P, so as to permit the lever G, to reset the mechanism as
described, it is necessary to provide means for indicating the condition of the
mechanism for operating the call-bell. With that view a hole Q is made through
the door N, and behind this hole we pivot an indicating plate R. This indicating
plate has two colors painted on it, one color,-say blue, to indicate that the mechanism
is set to operate the call-bell I, while the other color-say white, is intended to
indicate that the mechanism is set to operate the auxiliary call-bell.
As shown in figure 2, the plate R, is set to indicate the blue signal, and is held in
position by the pin a, which is fixed to the lever G, and projects behind the pin b,
fixed to the indicating plate R. d is the pivot-point of the plate R, from which pivot
a weighted arm S, fixed to the annunciator plate R, projects. The arm S, is shaped
so that it will project over the top of lever O, when the door N, is closed. When
the first signal is sounded, and the lever G, is caused to rock on its pivot as before
described, the pin a, is carried away from the pin b, and the weighted arm S, causes
the indicating plate R, to rock on its pivot and bring the white signal in front of the
hole Q, thus indicating that the mechanism is set for operating the auxiliary bell
instead of the bell I. When the receiver P, is removed and the lever O, is lifted,
the said lever comes in contact with the arm S, forcing it upwardly so as to bring
the indicating plate R, back into its initial position; the pin a, being simultaneously
brought in front of the pin, b, and thus the whole mechanism described is reset by the
action of the said lever O.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed I declare that what
I claim is:
1) A telephone call-bell connected to the telephonic circuit in such a manner that
upon being signalled its action breaks the circuit leading to the telephone call-bell
and switches the said circuit onto a line leading to an auxiliary call-bell situated at a
point remote from the telephone.
2) The wire A, and wire L, connected to the magnet C, and the wire B, connected
to the plate D, the spring E, arranged to form an electrical connection with the
lever G and plate D, and the magnet C, in combination with the armature H, lever G,
pin J, and wire K, arranged; substantially as and for the purpose hereinbefore:
described.
3) The wire A, and wire L, connected to the magnet C, and the wire B, connected
to the plate D, the spring E, arranged to form an electrical connection between the
plate D, and the magnet C, in combination with an armature H, lever G, pin J, wire K,
and air or oil cushion formed by the cylinder M, arranged; substantially as and for
the
purpose hereinbefore described.
4) The pivoted lever G, arranged to engage with a notch in the armature H, and
to project over the pivoted lever O, in combination with the spring E, arranged
substantially as and for the purpose hereinbefore described.
5) The pivoted indicating plate R, having a weighted arm S, fixed to it and designed
to extend over the pivoted lever O, in combination with the pins a and b, arranged
substantially as and for the purpose hereinbefore described.
Dated this 23rd d
1000
:
TONGUE & BIRKBECK,
34, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.