An Improvement in Electric Railway Signals.
Year: 1888

page_text: Date of Application, 3rd Nov., 1888
Complete Specification Left, 1st Aug., 1889-Accepted, 7th Sept., 1889
PROVISIONAL SPECIFICATION.
An Improvement in Electric Railway Signals.
I, ALEXANDER SIEMENS, of 12 Queen Anne's Gate, Westminster, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to signals of a kind more especially suited for electric railways
where powerful currents of electricity are available, these signals being so arranged
that they are set by the passage of trains over certain parts of the line, and sets of
such signals, applied to the successive block sections of the line, constitute an automatic
system requiring no attendants for working them. For this purpose at or near each
end of a block section of the line I provide a signalling apparatus of the following
description. On a horizontal axis is fixed a semaphoro arm or a set of coloured glasses
or both, these being counterweighted by a heavy arm on the axis so that when the
axis is free the signals are moved by the counterweight to the attitude signalling
"danger." The heavy arm is a bar of iron bent to the form of a circular are and
arranged so that it can enter a solenoid coil.
When this solenoid is excited by a current of electricity the iron bar is attracted
into it and then the axis is turned moving the signal to the attitude indicating "line
clear." The signal axis carries another arm which in case of its two positions makes
a contact, and in one of the positions, corresponding to the "line clear" attitude of
the signal this arm is held by a catch on the armature of an electro magnet. The coils
of this electro magnet are connected with a contact apparatus arranged at a certain
part of the line entering a block section so that when a train passes over this contact a
current of electricity is transmitted to the electromagnet and the core being thus
excited attracts its armature withdrawing the catch from the arm of the signal axis
whereupon the signal in obedience to the counterweight assumes the "danger" attitude.
At the same time the arm, released from the catch, moves away breaking the contact
for the electro magnet and making a contact whereby a current is transmitted to the
next signalling apparatus behind and this current exciting the solenoid then causes
the signal there to take the "line clear" attitude.
On the train reaching the next contact apparatus a like action is repeated the train
thus automatically blocking each section that it enters, and not unblocking it until it
enters the next section in advance.
From the description it is apparent that the signal at the beginning of a section
cannot be set at "line clear" unless the signal at the beginning of the next section
stands at "danger."
Although this control of one signal by the other is only described for the simplest
case, it is obvious that the electrical connections of three or more signals can be
combined so that each signal can only be set to show "line clear," when certain other
signals are at "danger."
Dated this 3rd day of November 1888.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Electric Railway Signals.
I, ALEXANDER SIEMENS of 12 Queens Anne's Gate, Westminster, in the County of
Middlesex, Civil 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:―
My invention relates to signals of a kind more especially suited for electric railways

page_text: where powerful currents of electricity are available, these signals being so arranged
that they are set by the passage of trains over certain parts of the line, and sets of such
signals applied to the successive block sections of the line constitute an automatic
system requiring no attendants for working them. For this purpose, at or near each
end of a block section of the line I provide a signalling apparatus of the following
description.
On a horizontal axis is fixed a semaphore arm or a set of coloured glasses or both,
these being counterweighted by a heavy arm on the axis so that, when the axis is free,
the signals are moved by the counterweight to the attitude signalling "dangor."
The heavy arm is a bar of iron hent to the form of a circular arc and arranged so that
it can enter a solonoid coil. When this solenoid is excited by a current of electricity
the iron bar is attracted into it and then the axis is turned, moving the signal to the
attitude indicating "line clear."
The signal axis carries another arm which in each of its two positions makes a
contact, and, in one of the positions corresponding to the "line clear" attitude of
the signal, this arm is held by a catch on the armature of an electro magnet.
The coils of this electro magnet are connected with a contact apparatus arranged
at a certain part of the line entering a block section so that, when a train passes
over this contact, a curront of electricity is transmitted to the electro magnet and
the core being thus excited attracts its armature withdrawing the catch from the
arm of the signal axis, whereupon the signal, in obedience to the counterweight,
assumes the danger" attitude. At the same time the arm, released from the
catch, moves away breaking the contact for the electro magnet, and making a
contact whereby a current is transmitted to the next signalling apparatus behind,
and this current exciting the solenoid there causes the signal there to take the
"line clear" attitude. On the train reaching the next contact apparatus, a like
action is repeated, the train thus automatically blocking each section that it enters,
and not unblocking it until it enters the next section in advance.
From the description it is apparent that the signal at the beginning of a section
cannot be set as 66
line clear" unless the signal at the beginning of the next section
stands at "danger."
Although this control of one signal by the other is only described for the simplest
case, it is obvious that the electrical connections of three or more signals can be
combined so that each signal can only be set to show "line clear," when certain
other signals are at " danger."
Figs. 1 and 2 of the accompanying drawings are vertical sections on planes at right
angles to each other, of signalling apparatus according to this invention. A is the
axis on which is fixed the semaphore arm or pair of coloured glasses, counterweighted
by the bent iron bar B which enters the heart of the solenoid C and is of sufficient
weight to hold the signal in the "danger" position. E is the electro magnet the
spring armature F of which terminates in a catch which holds an arm D.fixed on the
axis A. The arm D, or it might be another arm fixed on the axis A, is arranged to
act as a switch, making and breaking contacts for conductors to the solenoid and
electro magnet in the following manner.
As
Assuming that a train is running along a section of line from X station to Y station,
tbat the signal at X is at "danger" blocking the section against the entrance of another
train, and that the signal at Y is at "line clear" shewing that the train may enter
the next section from Y to Z. in that case the apparatus at X has its bar B and
arm D in the position indicated by the dotted lines B¹ and D¹, but the apparatus
at Y has the bar B within the solenoid and the arm D held by the catch of F.
the train leaves the section X to Y and enters the section Y to Z, it, by acting on a
contact apparatus on the line causes a current to pass through the coil of the
electro-magnet E at station Y. The armature F being thus attracted, the catch
holding D is withdrawn, and the bar B assumes the dotted position B₁ the signal
at Y being thus set to danger blocking the section Y to Z. At the same time D
in moving to the position D breaks the contact for the electro magnet E and
makes another contact whereby a current is transmitted to the solenoid C at
ور

page_text: station X. The solenoid there attracts the bar B setting the signal to "line clear"
indicating that the section X to Y is clear, and the signal at X is retained at "line
clear
by the catch of F holding D until it is released by a succeeding train entering
the section X to Y.
"
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 :-
Electric railway signal apparatus, constructed and operating substantially as
described with reference to the accompanying drawings.
Dated this 1st day of August 1889.
ABEL & IMRAY,
Agents for the Applicant.