Improvements in Cable Transmitters.
Year: 1894

page_text: Date of Application, 26th June, 1894
Complete Specification Left, 25th Mar., 1895-Accepted, 27th Apr., 1895
Improvements in Cable Transmitters.
I, HERBERT ARNAUD TAYLOR, M.I.C.E. of 4 Great Winchester Street, in
the City of London, do hereby declare the nature of this invention to be as
follows:-
There have lately been introduced modifications of the well known Wheatstone
automatic transmitter adapting it for the transmission of signals on a submarine
cable worked on the siphon-recorder or mirror system in which the formation of an
alphabet depends, not on the length of the elements (dots and dashes) but on their
direction.
To produce an excursion of the receiving organ to the left and its return towards
zero (equivalent to a dot) the distant end of the cable is applied first to one
pole of a battery (say zine) and then to "earth," whilst to produce an excursion to
the right and return towards zero (equivalent to a dash), the distant end is applied
first to the other pole of the battery and then to "earth."
In the Wheatstone automatic transmitter as hitherto constructed for cable
29
signalling the alternate application of the cable to battery and " earth is controlled
by the action of a "rocking lever" and it is not possible by this means to vary
the relative duration of the battery and earth contacts except within narrow
limits.
.
It has been observed that the signals received on a cable are smaller when
sent automatically than when sent manually with the same battery power and at the
same speed and I have found that this disparity may be removed by prolonging the
battery contact relatively to the earth contact.
I effect this by dispensing with the rocking lever and substituting for it a pair
of cams as is indicated in the drawing annexed the first cam a is fixed on a
prolongation of the arbor which usually carries the crank for working the rocking
fever. The second cam is moveable about the same axis as the first and can be
clamped thereto in any relative angular position.
These cams control the motion of the needle levers c and d through the inter-
vention of the crank lever e.
The fixed cam a is so shaped that the crank lever whose roller f rests against the
cam, allows the needle levers to rise at the instant that a signal hole in the paper
is or may be just over the upper end of one or other of the needles and imme-
diately after depresses them so that the tops of the needles are just below the level
of the paper.
If when they are allowed to rise there is no signal hole in the paper, both needles
press for an instant against the lower surface of the paper but they do not rise
sufficiently to move the contact levers g and but if there is a signal-hole on either
side of the paper the corresponding needle passes through the hole and its contact
lever puts the cable in connection with one pole of the battery.
As the contact-levers g and are provided with "jockey-rollers" this state of
things lasts until the projection of the cam comes round to the roller of the crank
lever by means of which the contact lever is forced back into the line to earth
position.
Dated this 26th day of June 1894.

page_text: I, HERBERT ARNAUD TAYLOR, M.I.C.E., of 4 Great Winchester Street, in
the City of London, 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 :---
There have lately been introduced modifications of the well-known Wheatstone
automatic transmitter adapting it for the transmission of signals on a submarine
cable worked on the syphon recorder or mirror system in which the formation of
an alphabet depends, not on the length of the elements (dots and dashes) but on
their direction.
To produce an excursion of the receiving organ to the left and its return towards
zero (equivalent to a dot) the distant end of the cable is applied first to one
pole of a battery (say zine) and then to "earth," whilst to produce an excursion
to the right and return towards zero (equivalent to a dash), the distant end is
applied first to the other pole of the battery and then to "earth."
In the Wheatstone automatic transmitter as hitherto constructed for cable
signalling the alternate application of the cable to battery and "earth" is controlled
by the action of a "rocking lever," and it is not possible by this means to vary
the relative duration of the battery and earth contacts except within narrow
limits.
It has been observed that the signals received on a cable are smaller when sent
automatically than when sent manually with the same battery power and at the same
speed and I have found that this disparity may be removed by prolonging the
battery contact relatively to the earth contact.
I effect this by dispensing with the rocking lever and substituting for it a pair
of cams as is indicated in the drawing annexed to my Provisional Specification.
The first cam a is fixed on a prolongation of the arbor which usually carries the
crank for working the rocking lever." The second cam is moveable about the
same axis as the first and can be clamped thereto in any relative angular position.
These cams control the motion of the needle levers c and d through the inter-
vention of the crank lever e.
The fixed cam a is so shaped that the crank lever whose roller rests against
the cam, allows the needle levers to rise at the instant that a signal hole in the
paper is or may be just over the upper end of one or other of the needles and
immediately after depresses them so that the tops of the needles are just below the
level of the paper.
If when they are allowed to rise by the cam there is no signal hole in the paper,
both needles press for an instant against the lower surface of the paper but they do
not rise sufficiently to move the contact levers y and h but if there is a signal
hole on either side of the paper the corresponding needle passes through the hole
and its contact lever puts the cable in connection with one pole of the battery.
As the contact levers g and h are provided with "jockey-rollers" this state of
things lasts until the projection of the cam comes round to the roller of the crank
lever by means of which the contact lever is forced back into the line to earth
position.
In the position in which the parts are shown in the drawing the roller fis
upon the neutral or concentric portion of the cam a. The rotation of the axis will
immediately bring the roller on to the flat of the cam and then the needles
carried by the two T shaped levers c and d are (so far as the lever e is concerned)
free to be raised by the operation of springs in connection with them. The springs
are not shown in the drawing. If either of the needles be intended to rise a signal
hole in the paper will at the moment they are liberated be brought by the clockwork

page_text: to correspond with the point of the needle and the needle will rise through the
hole; otherwise the paper prevents the rise of the needle. Suppose the needle
carried by the lever è to pass through a hole, then the pusher attached to the upper
end of the contact lever will thrust the lever from left to right and the point at
the upper end of the lever will pass underneath its jockey roller from the left side
to the right; the jockey roller which is mounted upon a spring blade rising to
permit the point of the contact lever to pass. In this way the lever is made to
leave its left hand contact stop and go to its right hand contact stop. The contact
lever is connected with the telegraph line but otherwise is insulated. The right
hand stop is a battery pole say zine; the left hand stop being a copper pole of the
same sending battery. Hence the rise of the needle connected with the lever c
results in a reversal of the battery connection of the telegraph line. Similarly if
the needle connected with the T form lever d be permitted to rise the upper end of
the contact lever g is thrust from left to right, the jockey roller at its lower end
permitting it to pass and retaining it when it has passed.
The contact lever g is connected to earth (or in a way equivalent), its right hand
stop which is a copper pole of the sending battery, and its left hand stop is a zinc
pole. When as shown the levers g and are both connected to the same battery
pole, obviously the line is to earth and no current passes in the circuit but when
the position of either lever is changed then the current passes, the direction being
dependent on the contact lever which is moved.
The axis on which are the cams a and b being rotated continuously by the clock-
work, the neutral portion of the cam a beyond the flat comes round to the roller ƒ
immediately after the movement of one of the contact rollers g, h, has or may have
taken place; and so the roller f and the levers c and d are brought back to the
position shown in the drawing. The contact levers g h however remain as they
may have been placed so long as the roller is upon a neutral portion of the cam
and the jockey rollers hold the contact levers firmly against their contact stops.
The further rotation of the cam axis brings the cam to operate against the
roller and the cam being adjustable upon the axis it can be set to operate sooner
or later as may be desired. The lever e when moved by the cam b so operates upon
the levers c and d that the pushers connected with their lower ends thrust the lower
ends of the contact leversy and from left to right and bring the contact levers
back to the position shown by the drawing. The pushers it will be seen are
adjustable along screw stems and they should be adjusted to operate in the manner
described. The contact stops are also adjustable.
Thus it will be seen that if a needle rises when the flat of the cam a passes the
roller the connection of the battery with the telegraph circuit is effectually
established and the connection is continued during a large portion of the rotation
of the cam shaft as may be desirable and until the cam 6 passes the roller f; then
during the remainder of the rotation of the cam shaft the telegraph line becomes
connected with earth (or its equivalent) the contact levers g and then resting
against stops which are connected the one with the other.
Obviously in place of the two cams a and b a single cam can be made which will
operate in the same way, the proper form having been ascertained by experiment,
but the double or adjustable cam is the more convenient.
Sometimes I slightly modify the mechanism by using two cams acting upon two
separate rollers and levers. For putting on the battery the cam a operates by
means of the lever e and roller precisely as already described; but for taking off
the battery another cam on the same axis operates upon another lever. This second
lever is similar in form aud position to the lever e so far as its upper limb is
concerned but it is not a right angle lever like e but straight; it extends downwards
below the fulcrum and to its lower end a stem is attached carrying the two pushers
which operate against the lower ends of the contact levers g and h. A spring
holds the roller at the upper end of the lever against the cam. The cam is similar
in form to the cam a and when the flat upon it comes to the operative position the
spring moves the lever and causes the pushers to act on the lower ends of the

page_text: contact levers and h. The pushers immediately return and leave the contact
levers in the "line to earth" position.
Thus according to this modification the lower pushers as well as the upper are
caused to advance by a spring and are withdrawn by the operation of the cam.
.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. My improved Wheatstone automatic transmitter for cable signalling which is
constructed substantially as described so that the battery contact is prolonged
relatively to the earth contact.
2. My improved Wheatstone automatic transmitter for cable signalling which is
so constructed substantially as described that the relative durations of the battery
and earth contacts can be adjusted..
3. The combination of mechanism substantially as described and illustrated by
the annexed drawings.
DAL
101 1
1005