Improvements in Semaphore Signal Apparatus.
Year: 1893

page_text: Date of Application, 11th July, 1893
Complete Specification Left, 24th Mar., 1894-Accepted, 28th Apr., 1894
[Communicated from abroad by Messrs. SIEMENS & HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improvements in Semaphore Signal Apparatus.
We, SIEMENS BROTHERS & CO. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a construction of semaphore signal apparatus such as
was described in the Specification to Patent No. 2068 of 1891 whereby the semaphore
arm is automatically brought from the "line clear” to the "danger" position, by
the passing of a train.
The object of the present improvements in the actuating apparatus is on the one
hand, to obtain by suitable transmitting devices a sufficient reduction of the con-
siderable force that is required for holding the semaphore arm in position, to
enable such holding, as also the releasing to be effected with certainty by weak
battery currents, and on the other hand, to avoid the severe shocks occurring on
the resetting of the apparatus, which in the previous construction acted injuriously
on the apparatus.
We will proceed to describe the improved construction with reference to the
accompanying drawing in which Fig. 1 shews the apparatus with the semaphore
arm in the "line clear" position. Fig. 2 with the arm set to the "danger" position
by the passing of a train while Fig. 3 shews the normal position of the parts for
the "danger" signal. The carrier lever c which has the same construction and
mode of operation as described in the Specification No. 2068 of 1891 is connected
by rod g with the releasing mechanism A.
The
The rod g effects the turning of a three-armed lever h, the arms i and k of which
engage respectively with the locking lever and the armature lever m.
position which the several parts occupy when in the normal "danger " position is
shewn at Fig. 3 where the rod g is in its lowest position and lever holds the
locking lever as also the armature lever m in definite positions, so that the lower
end of the locking lever is situated behind the notched axis of the armature
lever m, the armature of which is in contact with the electro magnet E.
Any slight downward motion of g would not alter the positions of levers and m,
as the parts of these which bear against the arms of lever hare formed as circular
arcs struck from the centre of h. If now the signal lever H Fig. 2 be moved into
the "line clear" position, the actuating lever S connected to the signal lever by
the pulls indicated by dotted lines, in being moved in a corresponding manner,
will exert a pressure upon the axis of the carrier lever e (which is carried by a
g to rise
crank arm on the signal post) and will in the first instance cause the rod
whereby the arms i and k will be made to leave the arc-shaped surfaces of land m,
i being made to bear against the shoulder n of lever which will consequently tend
to turn on its pivot, but will be prevented from doing so by its lower end butting"
against the notched axis of the armature lever m, as shewn in the position at
Fig. 1, the armature lever being then held in this position, although it has lost the
support of the arm h, because at the commencement of the before mentioned motion
of the signal lever H, the electric circuit of the electro magnet E will have been
automatically closed, causing this to attract the armature.
In consequence of the resistance of lever to further motion, the rod g cannot

page_text: rise any higher, and consequently the further motion of the actuating lever S into
the position shewn in Fig. I will cause the semaphore arm F to be raised by the
carrier lever c, by means of the pin d in the lever's slot, into the "line clear
position as shewn at Fig. 1.
>
Should it be desired to set the signal to "danger" again by the signal lever
before a train has passed, it will be seen that this can be readily done, as there is
nothing to prevent the lever h from re-occupying its position at Fig. 3.
If on the other hand while the signal is in the position at Fig. 1, a train in
passing depresses by its front wheel the lever P of a circuit breaker Fig. 2, so as
to break the circuit of electro magnet E, this will cease to attract the armature on
lever m and consequently this will fall by gravity, with or without the aid of a
spring, into the position shewn, thereby turning its notched axis into such a position
that the end of lever can pass the notch, so that lever his now free to turn in
following the upward pull of rod g, due to the downward pressure of semaphore
arm F on lever c and consequently the arm will automatically descend into the
danger position again, while the actuating lever S is still held in the position
for the line clear" signal by the signal lever H.
On now setting this lever and consequently also lever S into the " danger"
position again, S will lower the pivot of lever c, and as the outer end of this is
held by the pin d of the semaphore, its inner end will move downwards, thus
allowing rod 9. to descend, and causing lever h to turn back into the position at
Fig. 3, in which motion the arm i, in bearing against shoulder q of locking lever l,
will also bring this back to its original position, after which the arm k in bearing
against the surface p of the armature lever m, will also bring this back into the position
at Fig. 3, with the armature in contact with the electro magnet, and with the arms i
and bearing on the circular arcs of land m. The electro magnet is however still
inoperative, the circuit being broken.
The rod g which in the last described motion is pushed downwards, is provided
with a hinge joint as shewn so that no excessive pressure can be exerted
upon the lightly constructed locking gear, as the rod is capable of bending
laterally. This jointing also enables the correct position of rest of the lever to
be determined by stops, while the setting gear, in order to insure the lever h
reaching these stops and consequently the exact position of the locking gear, may
be arranged to have a motion slightly in excess of that required for this purpose.
But in order to afford the necessary force required to be exerted by the rod g to
perform the work of actuating the locking gear in the manner described, the lower
part of the rod g is loaded with a weight the pressure of which is sufficient to
insure the correct return of the armature lever m into its raised position.
"
This weight has the farther purpose of reducing the force of the pull exercised
on the rod 9 and the releasing gear by the semaphore arm when standing at "line
clear and to serve as counterweight on the descent of the arm. If the weight
which is sufficient for properly actuating the locking and releasing gear should not
be sufficient for the last named purpose, a second weight might be attached to the
rod g at a point above the hinge joint.
The electric circuit of the electro magnet is closed as soon as the signal lever H
is moved out of the danger position, or rather, as soon as the locking trigger is
moved, by means of the contact K, and it remains closed until the circuit breaker P
is actuated by a passing train, or until the signal lever is moved back to the "line
clear" position.
In the former case the armature falls away from the electro magnet, and by the
turning of its axis effects a second breaking of the circuit by means of a sliding
contact as indicated at Figs. 4 and 5, so that when the passing train releases the
current breaker P, this can at once fall back upon its contact without closing the
circuit. In the circuit may also be included a miniature semaphore indicator or
other known form of indicator for shewing at the signalling station, the position
of the semaphore arm.
°

page_text: The described construction also serves as an indicator of the proper condition of
the electric battery, as, should the current be too weak, the armature lever would
fall away from the electro magnet, and, in thus liberating the locking lever 1, it
would prevent the semaphore arm from being brought into the "line clear" position,
the moving of the signal lever H only having the effect of raising the rod g.
Instead of converting the up and down motion of the rod g into a rotating motion
of the lever h, the motion of the rod g might be directly utilised, which would only
requiré slight modifications of the mechanism.
Also, the actuating device S can be variously arranged, and the mechanism may
be adapted to operate with a lowered angular position of the semaphore arm for
"line clear," instead of a raised one, and also for working signals with two or
more semaphore arms. The breaking of the electric circuit for releasing the
semaphore arm can also be effected by circuit breakers introduced at any convenient
point, in addition to the one operated by the train.
Dated this 11th day of July 1893.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Semaphore Signal Apparatus.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate;
Westminster, in the County of Middlesex, Electrical Engineers, 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 :-
This invention relates to a construction of semaphore signal apparatus such as
was described in the Specification to Patent No. 2068 of 1891 whereby the
semaphore arm is automatically brought from the "line clear" to the "danger
position by the passing of a train.
"
The object of the present improvements in the actuating apparatus is on the one
band, to obtain by suitable transmitting devices a sufficient reduction of the
considerable force that is required for holding the semaphore arm in position, to
enable such holding, as also the releasing to be effected with certainty by weak
battery currents, and on the other hand, to avoid the severe shocks occurring
on the resetting of the apparatus, which in the previous construction acted
injuriously on the apparatus...
We will proceed to describe the improved construction with reference to the
drawing accompanying our Provisional Specification in which Fig. 1 shews the
apparatus with the semaphore arm in the "line clear" position. Fig. 2 with
the arm set to the "danger" position by the passing of a train while Fig. 3 shews
the normal position of the parts for the "danger" signal. The carrier lever c
which has the same construction and mode of operation as described in the
Specification No. 2068 of 1891 is connected by rod with the releasing
mechanism A.
The rod g effects the turning of a three-armed lever h, the arms i and k of which
engage respectively with the locking lever and the armature lever m. The
position which the several parts occupy when in the normal "danger" position is
shewn at Fig. 3 where the rod g is in its lowest position and lever h by means of
its arms i and k holds the locking lever as also the armature lever m in definite
positions, so that the lower end of the locking lever is situated behind the notched
axis of the armature lever m, the armature of which is in contact with the electro
magnet E. Any slight downward motion of g would not alter the positions of
levers and m, as the parts of these which bear against the arms of lever / are
formed as circular arcs struck from the centre of . If now the signal lever H
Fig. 2 be moved into the "line clear" position, the actuating lever S connected to the
signal lever by the pulls indicated by dotted lines, in being moved in a corresponding

page_text: manner, will exert a pressure upon the axis 6 of the carrier lever c (which is
carried by a crank arm on the signal post) and will in the first instance cause
the rod g to rise whereby the arms i and k will be made to leave the arc-shaped
surfaces of land m, i being made to bear against the shoulder n of lever / which
will consequently tend to turn on its pivot, but will be prevented from doing so by
its lower end butting against the notched axis of the armature lever m, as shown
in the position at Fig. 1, the armature lever being then held in this position,
although it has lost the support of the arm K because at the commencement of the
before mentioned motion of the signal lever H, the electric circuit of the electro
magnet E will have been automatically closed, causing this to attract the
armature.
In consequence of the resistance of lever I to further motion, the rod g cannot
rise any higher and consequently the further motion of the actuating lever S into
the position shewn in Fig. 1 will cause the semaphore arm F to be raised by the
carrier lever c, by means of the pin d in the lever's slot, into the "line clear"
position as shewn at Fig. 1.
Should it be desired to set the signal to "danger" again by the signal lever
before a train has passed, it will be seen that this can be readily done, as there is
nothing to prevent the lever h from re-occupying its position at Fig. 3.
If on the other hand while the signal is in the position at Fig: 1, a train in
passing depresses by its front wheel the lever P of a circuit breaker Fig. 2, so as
to break the circuit of electromagnet E, this will cease to attract the armature on
lever m and consequently this will fall by gravity, with or without the aid of a
spring, into the position shewn, thereby turning its notched axis into such a
position that the end of lever I can pass the notch, so that lever his now free to
turn in following the upward pull of rod g due to the downward pressure of
semaphore arm F on lever c and consequently the arm will automatically descend
into the "danger" position again, while the actuating lever S is still held in the
position for the "line clear" signal by the signal lever H.
""
On now setting this lever and consequently also lever S into the "danger'
position again, S will lower the pivot 6 of lever c, and as the outer end of this is
held by the pin d of the semaphore, its inner end will move downwards, thus
allowing rod g to descend, and causing lever h to turn back into the position at
Fig. 3, in which motion the arm i, in bearing against the shoulder 9 of locking
lever 1, will also bring this back to its original position, after which the arm k in
bearing against the surface p of the armature lever m, will also bring this back
into the position at Fig. 3, with the armature in contact with the electromagnet,
and with the arms i and k bearing on the circular arcs of land m. The electro-
magnet is however still inoperative, the circuit being broken. The rod g which in
the last described motion is pushed downwards, is provided with a hinge joint as
shown so that no excessive pressure can be exerted upon the lightly constructed
locking gear, as the rod g is capable of bending laterally. This jointing also
enables the correct position of rest of the lever h to be determined by stops, while
the setting gear, in order to insure the lever reaching these stops and consequently
the exact position of the locking gear may be arranged to have a motion slightly
in excess of that required for this purpose.
But in order to afford the necessary
force required to be exerted by the rod g to perform the work of actuating the
locking gear in the manner.described, the lower part of the rod g is loaded with a
weight the pressure of which is sufficient to insure the correct return of the
armature lever m into its raised position.
This weight has the further purpose of reducing the force of the pull exercised
on the rod g and the releasing gear by the semaphore arm when standing at
"line clear" and to serve as counterweight on the descent of the arm.. If the
weight which is sufficient for properly actuating the locking and releasing gear
should not be sufficient for the last named purpose, a second weight might be
attached to the rod g at a point above the hinge joint.
The electric circuit of the electro magnet is closed as soon as the signal lever H

page_text: is moved out of the danger position, or rather, as soon as the locking trigger is.
moved, by means of the contact K, and it remains closed until the circuit breaker P
is actuated by a passing train, or until the signal lever is moved back to the
"danger" position.
In the former case the armature falls away from the electromagnet, and by the.
turning of its axis effects a second breaking of the circuit by means of a sliding
contact as indicated at Figs. 4 and 5, so that when the passing train releases the
current breaker P, this can at once fall back upon its contact without closing
the circuit. In the circuit may also be included a miniature semaphore indicator
or other known from of indicator for shewing at the signalling station, the position
of the semaphore arm.
The described construction elso serves as an indicator of the proper condition of
the electric battery, as should the current be too weak, the armature lever would
fall away from the electromagnet, and, in thus liberating the locking lever 1, it
would prevent the semaphore arm from being brought into the "line clear
position, the moving of the signal lever H only having the effect of raising
the rod g.
"
Instead of converting the up and down motion of the rod into a rotating
motion of the lever h, the motion of the rod g might be directly utilised, which
would only require slight modifications of the mechanism.
Also, the actuating device S can be variously arranged, and the mechanism may
be adapted to operate with a lowered angular position of the semaphore arm for
"line clear," instead of a raised one, and also for working signals with two or more-
semaphore arms. The breaking of the electric circuit for releasing the semaphore-
arm can also be effected by circuit breakers introduced at any convenient point, in
addition to the one operated by the train.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what.
we claim is :-
1. In semaphore signal apparatus such as was described in the Specification to
Patent No. 2068 of 1891, connecting the carrier lever c to the releasing gear A
through a weighted articulated rod g, for the purpose of limiting the transmission
of the pressure upon the releasing gear to a definite quantity and equalizing any
excess of motion of the gear, substantially as described.
2. In electrical releasing gear for semaphore signals, the use of a three armed
lever to whose one arm the rod g of the carrier lever c is connected while the
other arms i and k operate in connection with the locking lever and the armature
lever m in such manner that the rod 9 can only move upward when no current is
passing through the electromagnet E and the lever m has fallen away from it,.
while on the following upward motion of the rod g the locking lever is first
moved back behind the notched axis of the armature lever after which the latter
is again raised up in contact with the electromagnet on the following downward
motion of the rod g substantially as described.
3. In the releasing gear referred to in the preceding claim, constructing the
locking lever and armature lever m with arc shaped surfaces against which the
arms i and k of the lever / bear so as to hold them in position when no current is.
passing through the electromagnet, while when the position of the semaphore arm
is reversed by the hand lever H the consequent motion of lever his prevented by
such arc shaped surfaces from releasing the locking lever until after the electro--
magnet has received current for holding the armature lever m substantially as and.
for the purposes described.
Dated this out 1
1004
ABEL & IMRAY,
Agents for the Applicants..