Improvements in Interlocking Switch and Signalling Apparatus for Railways.
Year: 1897

page_text: Date of Application, 22nd Sept., 1897-Accepted, 13th Nov., 1897
"
COMPLETE SPECIFICATION.
Improvements in Interlocking Switch and Signalling Apparatus
for Railways.
I, FRIDOLF SCHAUMAN, of Mariedal, Stockholm in the Kingdom of Sweden,
Mechanical 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:-
The present invention relates to an improved locking arrangement for interlock-
ing switch and signalling apparatus for railways, said locking arrangement being
so contrived that the pulleys used in the apparatus for transmitting motion
to the signals and switches can be revolved only when occupying a certain position
in relation to each other.
The construction of the locking arrangement is such that one signal cannot be
moved to "safety" for one track until all switches belonging to this track have
been set in a certain manner and the signal at the opposite end of the track has
been given the position "stop." The act of revolving the first mentioned signal-
pulley into the "safety" position causes all switch pulleys belonging to it at the
lever-apparatus and also the pulley for operating the signal at the opposite end of
the track to be locked in their positions, and it will be impossible to stir them from
said positions until the first-mentioned signal pulley has been returned to the
"stop" position.
In the accompanying drawing
Figure 1 illustrates an elevation of a lever-apparatus provided with the locking
arrangement referred to.
Figure 2 is a section on the line A-B of Figure 1, and
Figure 3 is a detail view.
The lever-apparatus, as usual, consists of a shaft a permanently secured in a
stand and on which are loosely mounted the pulleys for operating the signals and
switches which by means of wire ropes are cach connected with a pulley attached
to the corresponding signal or switch. In Figure I there is shown as an example
a lever-apparatus having two signal cord-pulleys I, II and two switch cord-
pulleys I and I, belonging to the former of the two, one, I being adapted to be
locked in the two extreme positions of its corresponding switch while the other I,
can only be locked in one of the extreme positions of its corresponding switch.
Belonging to the other signal cord-pulleys II there is shown a single switch pulley
only in the figure, though any number of such pulleys can be made to belong to
it, as in the case of the pulley I. The locking arrangement for each interlocking
system (i.e. for each set of signal-and-switch-pulleys belonging to one end of a
track) is composed of a bar, c (or c₁) adapted to slide in a longitudinal groove b
(or b₁), made in the shaft a, and provided with a number of projecting pins d (or d₁),
one for each pulley belonging to a system. The sliding bar c (or c₁) extends to
the adjoining system (belonging to the opposite end of the track) and is also pro-
vided with a projecting pin d (or d₁) for engaging with the signal pulley II (or I)
of said system. It may be extended, however, to any or all of the switch pulleys
of this system as well and be provided with pins for engaging with these pulleys

page_text: if it is desired to lock the latter simultaneously with the signal, it being when
evidently necessary to provide the hubs of the said pulleys with an additional
slot
As mentioned, in the lever-apparatus shown in Figure I the bar c is
provided with pins for engaging with the pulleys I, I, I, and II. Said pins
enter into slots е, ₁₁ е е, extending through a portion of the circumference of
the hub of the corresponding pulleys and being so shaped that the slot e of the
signal pulleys, from the middle of the slot (corresponding to the " stop" posi-
tion), towards its ends curves off axially in opposite directions while the slots ₁, eq
of the switch are through their entire length situated in a plane perpendicular
to the axis of the shaft and at one or both ends have axially directed recesses f
f into which the respective pins can be pushed. For the sake of distinctness,
the slots of the pulleys are shown developed in a plan view in Figure 3. In the
pulleys I and II, which serve for setting the ordinary switches and must be
arranged so as to be locked in two positions, the two axially directed recesses, f, f₁,
of the slot are located at each end of the latter while in the pulley I, the recesses
are placed at the same end of the slot, since the latter pulley is intended to be
locked in one of the extreme positions only. Besides the curved slot previously
mentioned there is made in the hub of the signal pulley I and II a straight
slot e, of the same shape as that of the switch pulleys though having the axial
recesses f, f, located at the middle of the slot, this position corresponding to the
stop" position of the signal pulley.
"
to
The locking arrangement operates as follows: When one of the signal pulleys
is revolved in one direction its oblique slot e causes the pin d engaging with it to
be shifted axially together with the bar c to one side, according to the direction
in which the pulley is revolved. In order, however, to allow of this rotation the
position of the slots of the other pulleys must be such that they will not prevent
the motion in the corresponding direction of their respective pins which are rigidly
fixed to the said bar. In order that the position shown in Figure 1 (corresponding
main-track clear," for instance) shall be occupied by the signal pulley I, it is
necessary that the slot e, of the switch pulley I, shall previously have been set in
such a manner that its right hand recess f, will lie opposite the pin d (which
position it can occupy only when the branch track does not connect with the main-
track) and that the pulley I, be so located that the end e₂ of the slot provided
with the recesses f, f₁ be situated directly opposite its pin (in which position the
corresponding track is blocked, for instance). Moreover, the straight slot c. of
the other signal pulley II must occupy its central position (i.c. correspond to the
"stop" position of the signal belonging to it) and its switch pulleys occupy pre-
When
determined positions provided that the locking-bar extends to them as well.
the, signal pulley I is subsequently revolved to "safety," the pins of the locking-
bar enter the corresponding recesses of the slots (Figure 1), thus locking the
switch pulleys belonging to the same system in their proper positions while the
signal pulley II (and alternately the switch pulleys of the opposite end of the track)
is simultaneously locked in the "stop" position, and it will now be impossible to
stir said pulleys from their positions until the pulley I has again been revolved
into its central position, 2.e. for "stop."
In case of double slots being arranged in the switch pulleys, as previously
mentioned, the recesses f, f₁, of the slots may be given such direction that the sig-
nal at one end of the railway yard cannot be set in position "main-track clear"
(or side-track) until the switch at the other end of the same track has been set
for side-track (or main-track), it being thus made possible to avoid collision should
one train in spite of the stop signal run into the station simultaneously with the
arrival of another train from the opposite direction.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
An improved locking arrangement for interlocking switch and signalling

page_text: apparatus for railways, consisting of a fixed shaft (a) provided with longitudinal
grooves (b, b) and having revolubly mounted thereon pulleys (I, I₁, I, II) each
connected to its respective signal apparatus or switch and in each of the aforesaid
longitudinal grooves a sliding locking-bar (c, c₁), extending through the hubs of
all the pulleys (I, I₁, I₂) belonging to the same system and corresponding to one
end of the track, and into the hub of the pulley (II) for operating the signal
and, alternately, into the pulleys for operating any or all of the switches at the
opposite end of the track, said locking-bar being provided with projecting
pins (dor d) engaging with slots (e, e₁, c) extending through a portion of the
circumference of the hubs of the corresponding pulleys, the arrangement of these
slots being such that the slot of the signal pulley (I) of the system from the middle
of the slot, curves off toward each end in opposite directions axially while those of
the switch pulleys of said system through their entire length are located in a
plane which is perpendicular to the axis of the shaft and at one or both ends are
provided with axially directed recesses (f, f₁), into which the aforesaid
pins (d, d) enter when the signal pulley has been set in one of its extreme posi-
tions, and the hub of the pulley for operating the signal at the opposite end of the
railway yard besides its curved slot (e) is provided with a second slot (eg) parallel
to those of the switch pulleys and having at its middle axially extending recesses
opposite each other, all for the purpose of preventing the signal pulley of one
system from being shifted fronr stop safety" until the switch pulleys of
the system have been set in a fixed end-position and the signal at the opposite
end of the track has been placed at " stop," and, alternately, 'its switches in fixed
end-positions, and of locking the pulleys actuated by the said locking-bar in
their positions when the signal pulley is turned into the "safety" position.
to
Dated this 22nd day of September 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.