An Improvement in Telegraphic Apparatus for Railways.
Year: 1893

page_text: Date of Application, 2nd Mar., 1893
Complete Specification Left, 17th Nov., 1893-Accepted, 23rd Dec., 1893
PROVISIONAL SPECIFICATION.
An Improvement in Telegraphic Apparatus for Railways.
1, EDWARD TYER of Ashwin Street, Dalston in the County of London,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:
In my Specification No. 2575 of 1879 I described telegraphic apparatus by which
signalmen at railway stations could communicate with each other. In that
apparatus a make and break wheel was worked by clockwork through such part of
a revolution as was determined by a stop placed by the transmitting signalman at
such point of the revolution as he desired. By the series of alternating electric
impulses thus transmitted to the distant station a double crown wheel with inverted
teeth was caused, by the oscillations of a polarised armature, to turn and move an
index to a point on a dial corresponding to the stop point of the transmitting
instrument. My present invention relates to apparatus of this kind so modified
that the clockwork is entirely dispensed with, and that, instead of alternating
electric impulses, intermittent currents of one direction are employed for transmission.
For this purpose, I provide in the sending instrument a lever the end of which is
engaged between two oppositely toothed crown wheels on au axis, so that when
this lever is alternately pushed by a plunger and allowed to be moved back by a
spring, its reciprocations cause the crown wheels to move tooth by tooth round
until an arm upon their axis comes against a peg introduced by the operator in
any one of a number of holes on a dial. Every successive step by step movement
of the crown wheels causes a spring contact lever to suddenly break contact with
the receiving instrument at this station and to make a contact by which an electric
impulse is transmitted to the receiving instrument at the distant station. In this
instrument the reciprocating spring armature-lever of an electromagnet causes a
pair of crown wheels to turn step by step, so that an index on their axis is brought
round to a point on a dial corresponding to the point where the stop peg had been
placed in the transmitting dial.
Dated this 2nd dev of March 1802
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Telegraphic Apparatus for Railways.
I, EDWARD TYER, of Ashwin Street, Dalston in the County of London,
Electrical Engineer, 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 :-
In my Specification No. 2575 of 1879 I described telegraphic apparatus by which
signalmen at railway stations could communicate with each other. In that
apparatus a make and break wheel was worked by clockwork through such part of
a revolution as was determined by a stop placed by the transmitting signalman
at such point of the revolution as he desired. By the series of alternating electric
impulses thus transmitted to the distant station a double crown wheel with inverted
teeth was caused by the oscillations of a polarised armature to turn and move an
Price 1

page_text: index to a point on a dial corresponding to the stop point of the transmitting
instrument. My present invention relates to apparatus of this kind so modified
that the clockwork is entirely dispensed with and that, instead of alternating
electric impulses, intermittent currents of one direction are employed for transmission.
For this purpose, I construct the apparatus as I shall describe referring to the
accompanying drawings.
Fig. 1 is a perspective view of the instrument complete.
Fig. 2 is a front elevation the door at the lower part being removed to shew the
interior.
'
Fig. 3 is a vertical section, and Fig. 4 is a part sectional plan shewing the
receiving portion of the apparatus which is situated in the upper part of the
casing A, the sending portion being arranged in the lower part, which is closed
by a door B. Through the door B passes a plunger C an arm at the end of
which has a stud D bearing against a pad on a lever E. This lever is pressed
towards the door B by a rod protruding from a spring box F. The upper end of
the lever projects into the space between two oppositely toothed crown ratchet
wheels so that, as the lever E is moved to and fro by the push of the plunger C and
of the spring rod F, the wheels G are caused to revolve step by step. They are
fixed on a spindle which carries a wheel H provided with a number of cam teeth.
Over this wheel is mounted a contact spring I carrying a roller which every time
a tooth of H passes is caused to rise, breaking contact at J with the receiving
instrument above and making contact at K by which an electric current is trans-
mitted to the similar receiving instrument at a distant station. On the spindle of
the wheels G is fixed an arm L, on the door B is a dial plate M with a number of
circularly arranged holes through it and the door, and a pin N is provided which
the operator can insert into any one of the holes so as to meet the arm L and form
a stop for it at any desired part of its revolution.
In the receiving instrument situated in the upper part of the casing, there is a
pair of crown ratchet wheels 9 which are moved step by step round by the spring
armature a of an electromagnet m. The wheels g can also be turned by a spring
lever e that is oscillated by the alternate push and release of a plunger c. By the
rotation of the wheels g an index i on their spindle is caused to turn to any of the
divisions on a dial R, these divisions corresponding with the holes in the dial M.
The apparatus is operated in the following manner. The signalman, desiring to
send to the signalman at another station one of the messages marked on the dial R,
such for instance as "train waiting, 10" places his pin N in the corresponding
hole 10 of the dial M and then repeatedly pushes and releases the plunger C, thus
turning the wheels G step by step until the arm L is stopped by meeting the
pin N, when the plunger cannot be farther pushed. By the movement thus given
to the wheel H, causing oscillations of the contact lever I, a succession of electric
currents are transmitted to the electromagnet m at the distant station causing the
armature lever a to oscillate, this causing the wheels g to revolve step by step
until the index i is turned to the division 10 of the receiving dial. In like manner,
the signalman at the distant station, having a similar sending instrument, can
signal to the operator, who, after receiving the signal on his dial R, can move his
index i on to zero by acting on the plunger c.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In telegraphic apparatus for railways of the kind described in the Specification
No. 2575 of 1879, a sending instrument consisting of a plunger, spring lever, a
pair of crown ratchet wheels, a cam toothed wheel and contact lever, arranged
and operating in combination with a perforated dial and pin, substantially as
described.
2. In combination with a sending instrument such as is above referred to.a

page_text: receiving instrument consisting of an electromagnet spring armature and plunger
lever, a pair of crown ratchet wheels and an index arranged and operating substan-
tially as described.
Dated this 17th dow of November 1893
ABEL & IMRAY,
Agents for the Applicant.