Improvements in Apparatus for Obtaining Synchronous Movement at the Ends of Submarine Cable or other Telegraph Lines.
Year: 1898

page_text: Improvements in Apparatus for Obtaining Synchronous Movement at
the Ends of Submarine Cable or other Telegraph Lines.
SIDNEY GEORGE BROWN, Van Buren, Poole Road, Bournemouth (County of
Southampton), do hereby declare the nature of this invention to be as follows:-
It is necessary for the transmitters at each end of the line to run in step with
each other, so that they may be enabled to send their respective signals in succes-
sion into the line.
One way to keep them in step is to fix to a convenient part of their revolving
mechanism, say to that part that drives the tape, an escape wheel. To the escape-
ment lever is fixed a polarized steel tongue.
This tongue is urged backwards & forwards by electromagnets placed each side
of it, the electromagnets being operated through special contacts placed on the
synchronizing contact maker. The synchronizing apparatus may be of any suit-
able construction and be controlled preferably by a pendulum or a chronometer
balance wheel.
One arrangement of synchronizing apparatus however which I
propose to
employ has a combination with a pendulum a tuning fork or reed which controls
a make and break contact in the circuit of one or more electromagnets. One or
more of these magnets act on the cogged or toothed periphery of an iron disc or
wheel forming part of the revolving contact maker.
The other magnet or magnets act on the limbs or limb of the tuning fork or
reed and keep them or it in vibration.
For enabling the pendulum to control the speed of the contact maker the latter
is provided with two semicircular contact bands or segments the ends of which are
separated by narrow gaps.
A pair of oppositely arranged brushes press on the segments and convey to them
momentary currents from a circuit controlled by the pendulum.
Another pair of oppositely arranged brushes approximately at right angles to
the first pair form part of a relay circuit.
The arrangement is such that when the contact maker is working at the proper
speed the latter brushes bridge the gaps between the contact bands or segments
at the instant the pendulum completes the aforesaid circuit the current in the
latter travels direct from one segment to the other through the tips of the relay
brushes no current however flowing into the relay circuit.
If however the speed of the contact maker varies the two relay brushes will at
the moment the circuit is completed be pressing upon opposite segments and a
difference of potential will exist between them which will energise the relay in
their circuit. This latter controls a ratchet and pawl or other device for adjusting
the position of a damping weight on the tuning fork or reed.
If the speed be too high the relay brushes will at the moment the pendulum
circuit is completed be pressing on opposite segments to those which they will
press on if the speed be too low & the relay will move the damping weight

page_text: If the speed be too high, the relay brushes will at the moment the pendulum
circuit is completed, be pressing on opposite segments" to those which they will
press on if the speed be too low, and the relay will move the damping weight
accordingly, to reduce or to increase the rate of vibration of the tuning-fork or
reed, and thereby that of the contact maker, which, is as stated, controlled. by the
said fork or reed.
Referring to the drawing which illustrate the arrangement at either end of the
line.
D represents one of the revolving contact makers, having fixed to it any arrange-
ment of brushes and contact pieces.
It is desired to keep D rotating synchronously with another and similar con-
tact maker, situated at another part of the line.
P is the controlling pendulum.
It is eccential that P should perfectly controll the speed of rotation of D and
at the same time keep step with the other pendulum, (which is connected with
the distant contact maker), for reasonable lengths of time.
The contact maker D is driven by means of the iron cogged. or toothed peri-
phery, acted on by the electromagnets C.
These electromagnets receive periodic currents from a battery through the con-
tact breaker B.
These periodic currents also pass through the electromagnet N which acts on
the limbs of the tuning-fork T, and keep them in vibration, which in their turn
keep the contact breaker B in motion.
The pendulum P is fitted with a suitable contact maker, such as the metal
point, and the globular of mercury M, so that at the mid point of every swing
the potential of a local battery can be applied by means of the contact brushes G, H,
to the segments J, K, these segments being fixed to the contact maker D.
E, F,Care two other contact brushes placed in such a position that they bridge
the gaps between the segments J, K, at the instant the pendulum P completes the
circuit, provided the contact maker is running at the proper speed.
Supposing the contact maker was rotating in a clockwise direction, and at too
high a speed, then when the pendulum completed the circuit the brushes E, F,
would not be resting on the gaps between the segments, but further back on the
segments K, J, the current in this case flowing from the battery to G, through F,
thence passing through the polarized relay R, through E to H, through M, back
to the battery.
This momentary flick of current would cause the armature of the polarized
relay R, together with the pawl Q, to move, say over towards the ratchet A,
rotating the ratchet say one tooth forward, screwing the moveable damping
weights further up the arms of the tuning-fork T, decreasing their time of vibra-
tion and thence in turn, the speed of rotation of the contact maker D.
If I happened to be too slow then the reverse action would take place the
damping weights W, W, being moved further down the arms of the tuning-fork T,
every time the contact making point on the pendulum passed over the mercury M,
and this would continue, till the contact maker D was in correct step with P
and E, F, bridging the gaps as before.
It is manifestly impossible that the pendulum P however carefully made and
adjusted, should continue to beat in unison with the distant pendulum, but the
variation may be sufficiently slow to allow of easy manual adjustment by observa-
tion of the received signals, this being most easily done by altering the position
of the brushes, which work off the extra contacts of D, rotating them with or
against its motion, or an adjustable weight could be moved on P, raising or
lowering, its time of swing, as should be thought most convenient.
In some cases it might be possible by means of suitable attachments, to cause
the receiving instruments, themselves to effect the necessary alteration, auto-
matically, and in special cases if the line allowed of such a procedure, correcting