IMPROVEMENTS ELECTRIC CALL SIGNALS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Herbert John Haddan at the Office
of the Commissioners of Patents on the 23rd December 1881. A communi-
cation from abroad by Gay Wilson Foster and Floyd Baker Wilson, both of
Paris, France.
IN
HERBERT JOHN HADDAN of Kensington, Middlesex. "IMPROVEMENTS
ELECTRIC CALL SIGNALS." A communication from abroad by Gay Wilson Foster
and Floyd Baker Wilson, both of Paris, France.
The improvements consist of clock work provided with an escapement in
combination with a double helix, furnished with a metallic rod, having an
armature on one end, said armature being placed directly in front of the helix for
the purpose of being attracted towards said helix by passing a current of electricity
through the same. The slightest movement of the armature caused by the current
being broken releases the escapement and allows the main spring in the clock
work to run down or unwind and in so unwinding causes a haminer connected
with the said clock work to strike a metal gong and give forth a series of taps or
a single tap on the gong to attract the attention of any one in the immediate
neighbourhood of the instrument.
The post connected with the said spring is provided with a knob which protrudes
through a hole in the case or box holding the mechanism, enabling one to wind up
the spring without opening the box.
The winding up of the spring to its fullest capacity causes a lever to be moved
away from a small metallic binding post or connector as far away, as desired and
thereby breaks the circuit or electric current and allows the armature to inove by
being demagnetized, this action releasing the clock work escapement, and allowing
the main spring to unwind and the hammer to strike the gong, as the spring
unwinds the lever separated from the connector gradually moves back to its
original position, finally striking the metal connector, completing the circuit through
the helix, and attracting the armature towards the helix, which action throws a
lever against the escapement which lever acts as a brake, and stops the movement
of the wheels in the clock work, stopping the movement of the hammer, and the
ringing of the signal, till the main spring is again wound up sufficiently to again
break the electric circuit, as before mentioned. Therefore one of the principal

page_text: advantages derived from this signal is the fact that in case a telephone, telegraphi
or other electric conducting wire having one or more of these signals in its circuit
should become broken, or in any way become in contact or connected with a
conducting substance leading to the earth thereby destroying or impairing the
electric current passing through this signals helix the effect on the signal would be
to demagnetize the helix, allow a movement of the armature on all of the signals
in the above named circuit thereby causing each of them to ring till the main
spring had run down, thereby instantly notifying the operator at each of the
stations that the line or wire is out of order and must be repaired before the
signals could again be made to perform their work.
By an alteration in the adjustment of the metallic rod in connection with the
escapement of the clock works the signal can be made to ring by closing the
electric circuit instead of breaking it as above described, by bending the rod or
lever so as to act as a brake on the escapement so long as there is no electric
current on the line or wire connecting with the signal, and so as to signal by a
movement of the armature and metallic rod said movement being caused by
sending a current of electricity through the helix of said signal. Therefore one of
the great improvements claimed is the action of this signal when operated either
on an open or closed circuit.