Improvements in Railway Signalling Apparatus.
Year: 1891

page_text: Date of Application, 22nd July, 1891
Complete Specification Left, 22nd Apr., 1392-Accepted, 28th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Railway Signalling Apparatus.
I, EDWARD RUSSELL of 12 Culverland Road, Exeter, in the County of Devon,
Signal Superintendent, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to insure as absolutely as possible that in the
majority of signals referring to shunting movements or other movements on railways,
that the signal referring to such movement where such signals are used in con-
nection with the switch points that the said switch points shall be perfectly home
in either direction before the said signal can be operated and when the said signal
has been operated it shall move to its proper "all right" position and shall not be
moved to what is termed a "doubtful position," on the one hand, and on the other
hand that in the return motion of the lever which operates the said signal should it
fail to operate it to the "danger" position the return motion of the switch points
themselves shall replace the said signal to the "danger" position.
At the present time it is the usual custom to operate a disc or shunting signal
independent of the points to which it refers. In regard to the detecting arrange-
ments, that is to say that the points may be half way open and the signal itself
referring to such points can be given "all clear," this of course is obviously a
dangerous proceeding and one which it is the object of my invention particularly
to overcome. Again where it is required that the signal itself shall work correctly
to the "all right" and "danger" positions, an electrical repeater is fitted in con-
nection with the arm. Such repeaters are costly and require maintenance. The
object of my invention is to make the mechanical working of the disc sufficiently
perfect to obviate the necessity of fixing such electrical repeaters and also to.
inake the return motion of the disc determined by the return motion of the points.
It will be clearly understood that the preceding description refers to where such
points are moved over to make a direction for the signal to be given "all clear."
It is obvious that where the points lie normally right for such signal that an
opposite arrangement must be provided and the working over of the points should
put the signal to "danger," and that unless the points are perfectly right in their
normal position the signal cannot be deflected.
I will now proceed to describe my invention.
My invention is applicable to either revolving discs or stationary discs, but I will
describe it for the purposes of illustration as applicable to a stationary disc. By a
stationary disc I mean a disc whose signal itself does not revolve but works in a
vertical position.
Attached to the stretcher bar of the switch poirts I arrange a prolongation
thereof and attached to such prolongation an ordinary bell crank is fixed, either
by a lug on such prolongation or by a double joint. At the end of the crank con-
nected to such extension of the stretcher bar is a blade which for the purpose of
description I will call a detecting blade. The said blade has one or two notches
in it as is desirable according to whether the points are provided with signals
for both ways or whether the signal is applicable to only one direction of the
points.
Arranged in the wire which operates the disc signal by the lever in the signal
box and at the end adjacent to the disc itself is a blade provided with a slot either
cut in the blade itself or a piece bolted on the top of the said blade forming a
loop, or a long loop at the end of the wire connected to the said blade. Into this
loop or slot or working in the said raised piece is the end of a crank connected to a
prolongation of the stretcher bar. The other end of the blade attached to the

page_text: wire is provided with a suitable detecting blade which is directly connected to the
signal and the said bolt is provided with a raised piece or notch or other means
which prevents it being operated unless the points are perfectly home in the
position desired for which the signal is intended to be given. The crank whose
end works in the slot in the signal detecting blade is in the normal position at the
end of the slot nearest to the signal and as the points are operated the detecting
slide attached to the stretcher bar is moved to clear the detecting blade attached
to the signal and the crank is also moved until its arm is moved to the other end
of the slot thereby allowing the signal to be operated. After the signal has
been operated it is usual for it to be replaced to "danger" first, but if the wire
should become hung up or by any means the signal fail to go to "danger," the
putting back of the points by means of the crank would operate on the end of the
slot or raised piece or loop on or in the blade connected to the wire and would
so place the signal to "danger." It should be provided in connection with the
detecting slide attached to the stretcher bar, that whereas the movement is definite
in working over the blade to free the signal, that is to say that the signal cannot
be operated unless the correct movement of the points has been given and the
notch thereby releasing the detecting slide attached to the signal yet upon the
return motion of the said points in the event of the wire becoming fastened any-
where or any obstruction offered to its travel, one side of the notch in the detecting
blade attached to the stretcher bar should be bevelled or rounded off to allow the
detecting blade to slide over the blade attached to the disc and be moved over
thereby putting the signal to "danger," otherwise if straight notches were
provided the signal would backlock the points and prevent them being reversed.
Dated this 22nd day of July 1891.
EDWARD RUSSELL,
Applicant.
COMPLETE SPECIFICATION.
Improvements in Railway Signalling Apparatus.
I, EDWARD RUSSELL of 12 Culverland Road, Exeter, in the County of Devon,
Signal Superintendent, 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 object of my invention is to insure as absolutely as possible that in the
majority of signals referring to shunting movements or other movements on
railways, that the signal referring to such movement where such signals are used in
connection with the switch points that the said switch points shall be perfectly
home in either direction before the said signal can be operated and when the said
signal has been operated it shall move to its proper "all right" position and shall
not be moved to what is termed a "doubtful position," on the one hand, and on the
other hand that in the return motion of the lever which operates the said signal
should it fail to operate it to the "danger" position the return motion of the switch
points themselves shall replace the said signal to the "danger" position.
At the present time it is the usual custom to operate a disc or shunting signal
independent of the points to which it refers. In regard to the detecting arrange
ments that is to say that the points may be half way open and the signal
referring to such points can be given "all clear"; this of course is obviously a
dangerous proceeding and one which it is the object of my invention particularly
to overcome. Again where it is required that the signal itself shall work correctly
to the "all right" and "danger" positions, an electrical repeater is fitted in con-
nection with the arm. Such repeaters are costly and require maintenance. The
object of my invention is to make the mechanical working of the disc sufficiently
perfect to obviate the necessity of fixing such electrical repeaters and also to make
the return motion of the disc determined by the return motion of the points.

page_text: It will be clearly understood that the preceding description refers to where such
points are moved over to make a direction for the signal to be given "all clear."
It is obvious that where the points lie normally right for such signal that an
opposite arrangement must be provided and the working over of the points should
put the signal to "danger," and that unless the points are perfectly right in their
normal position the signal cannot be deflected.
I will now proceed to describe my invention.
My invention is applicable to either revolving discs or stationary discs, but I
will describe it for the purposes of illustration as applicable to a stationary disc.
By a stationary disc I mean a disc whose signal itself does not revolve but works
in a vertical position.
Attached to the stretcher bar of the switch points I arrange a prolongation
thereof and attached to such prolongation an ordinary bell crank is fixed, either
by a lug on such prolongation or by a double joint. At the end of the crank con-
nected to such extension of the stretcher bar or otherwise connected to the
stretcher bar of the switch points is a blade which for the purpose of description I
will call a detecting blade. The said blade has one or two notches in it as is
desirable according to whether the points are provided with signals for both ways
or whether the signal is applicable to only one direction of the points..
Arranged in the wire which operates the disc signal by the lever in the signal
box and at the end adjacent to the disc itself is a blade provided with a slot either
cut in the blade itself or a piece bolted on the top of the said blade forming a loop,
or a long loop at the end of the wire connected to the said blade. Into this loop
or slot or working in the said raised piece is the end of a crank connected to a
prolongation of the stretcher bar, or to a separate rod connected to the switch as
shown. The other end of the blade attached to the wire is arranged for suitably
detecting and the said end is provided with a raised piece or notch or other means
which prevents it being operated unless the points are perfectly home in the position
desired for which the signal is intended to be given. The crank whose end works
in the slot in the signal detecting blade is in the normal position at the end of the
slot nearest to the signal and as the points are operated the detecting slide attached
to the switch points is moved to clear the detecting blade attached to the signal
and the crank is also moved until its arm is moved to the other end of the slot
thereby allowing the signal to be operated. After the signal has been operated it
is usual for it to be replaced to "danger" first, but if the wire should become hung
up or by any means the signal fail to go to "danger," the putting back of the
points would operate on the end of the slot or raised piece or loop on or in the
blade connected to the wire and would so place the signal to "danger."
It should
be provided in connection with the detecting slide attached to the stretcher bar,
that whereas the movement is definite in working over the blade to free the signal,
that is to say that the signal cannot be operated unless the correct movement of
the points has been given and the notch thereby releasing the detecting slide
attached to the signal, yet upon the return motion of the said points in the event of
the wire becoming fastened anywhere or any obstruction offered to its travel, one
side of the notch in the detecting blade attached to the stretcher bar should be
bevelled or rounded off to allow the detecting blade to slide over the blade attached
to the disc and be moved over thereby putting the signal to "danger," otherwise
if straight notches were provided the signal would backlock the points and prevent
them being reversed.
In order that my said invention may be better understood and more readily
carried into effect I will proceed to describe the drawing hereunto annexed.
Figure 1 is a plan illustrating a switch showing its connection with a disc.
Figure 2 is a side elevation of the disc signal.
Figure 3 is a back elevation of the disc signal.
Figure 4 is a part view of the connection from the switch points forming the
detecting blade.
Figure 5 shows a part back view of the lower portion of the disc in which the

page_text: switch has been moved and the notch in the detecting blade thereby placed in front
of the signal slide.
Figure 6 is similar to Figure I but the points are shown worked and the signal
shown "all clear."
The same letters refer to the same parts in the several figures of the drawing.
a is the stretcher bar of the switch points, b is the switch. c the rod and
crank connections from the lever in the signal box which operates the switch points,
the connection from the switch points and through which they are detected,
the detecting blade, e the crank connected to the blade d,f the signal slide,
the disc, the wire through which the disc is operated, is the end of the signal
slide blade connected to the T lever which operates the disc, is the loop in the
signal slide blade in which the crank e operates, m is the carriage or bracket in
which the detecting slide operates, d is the notch in the detecting slide d², d³ is
the bevelled side of the said notch d².
It will be observed that the use of the Faid bevelled side is to enable the
points to be replaced to their normal position although the signal may be in the
safety attitude, the bevelled side allowing the detecting blade d' to ride over
the signal slide or locking blade. Although the drawing illustrates a separate
connection not attached to the stretcher bar of the switch points or the detecting
slide in connection with the disc to be worked, yet it is obvious that either the
stretcher bar may be prolonged or separate connections made from each tongue of
the switch points operating through the carriage m as one blade, or a continuation
may be provided of the rod which operates the switch points, as for instance, a
continuation of the rod connected to the end c¹ of the crank c, which extension
would be in lieu of the detecting slide d'.
A brief description of the working is as follows:- -The disc is desired to be
operated for movements through the switch points. In the normal position of the
points the disc g could not be operated as the notch in the detecting slide d'
would not be opposite the raised portion of the signal slide. When the points
are worked through the rod connections c the crank e is moved to the angle shown
in Figure 6, the detecting slide d' is moved until the notch is opposite the signal
slide, and the disc g is now free to be operated. By the movement of the wire h
through the lever in the signal box the disc g is lowered, the signal slide fis
thereby operated until the end of the loop travels almost in contact with the
crank e as shown in Figure 6, the blade k is moved through the notch d³ of the
detecting slide d' thereby ensuring that the points are home so long as the inter-
locking in the signal box remains intact, that is to say, so long as the point lever
cannot be replaced before the signal lever. Upon replacing the signal lever
putting the disc g to "danger," should the wire get hung up or in any way the
disc be prevented from moving to the "danger" attitude, the points when
replaced operate the crank e and by that means the loop on the signal slide ƒ
thereby replacing the signal to "danger."
My arrangements as described are applicable to where two movements are
needed through a pair of points, the normal position being the worked over position,
either by one disc for two such movements or by separate discs for two such
movements.
It is obvious that although my description has reference particularly to shunting
movements with two disc signals, yet I do not debar myself from using it in con-
nection with any signal or signals referring to any pair or pairs of points.
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. In railway signalling, apparatus arranged in such a manner that. a signal
referring to a pair of switch points cannot be operated to the safety attitude until
the points themselves are perfectly home in the desired position, the act of
returning the switch points to their normal position ensures such' signal being

page_text: replaced to its safety attitude, substantially in the manner herein set forth and as
illustrated in the accompanying drawing.
2. In railway signalling, apparatus ensuring that a signal referring to a pair of
switch points is returned to the safety attitude by the same motion in which the
switch points are returned to their normal position, substantially as herein
described.
3. Arrangements whereby a signal and a pair of points cannot be in opposition
to each other, that is to say, that the signal cannot be at "safety" unless the points
are home and in the desired position.
4. In railway signalling, arrangements whereby the replacing of points to their
normal position ensures the replacing of signals applying to such points to the
"danger" attitude.
JOHN P. O'DONNELL,
2, Great George Street, Westminster, London, S.W.,
Agent for the said Applicant.