Improvements in Machinery or Apparatus for Train Signalling on Railways.
Year: 1887

page_text: Date of Application, 4th Mar., 1887
Complete Left, 23rd Nov., 1887
Complete Accepted, 23rd Dec., 1887
PROVISIONAL SPECIFICATION.
Improvements in Machinery or Apparatus for Train Signalling
on Railways.
I SAMUEL TELFORD DUTTON of Marl Bank in the City of Worcester Civil Engineer
do hereby declare the nature of this Invention to be as follows:-
My invention consists of machinery or apparatus constructed and worked in the
manner hereinafter described by the use of which machinery or apparatus risk of
accident is avoided when by carelessness or inadvertance on the part of the signalman
or from other cause the signal lever is moved from the «
"
safe position to the
"danger" position before the train signalled has passed all the points controlled by
the signalling apparatus.
In order that my invention may be the better understood I remark that according
to the ordinary method of signalling the signalman keeps the signal off that is holds
it in its "safe" position until the train signalled bas passed through all the points and
parts of the line under the control of the signalling apparatus. Immediately he puts
back the signal lever to its "danger" position the levers working the points are
unlocked and if this unlocking is effected before the train has passed the parts
which should be locked during the passing of the train there is great danger of
accident.
The object of my invention is to prevent the risk of accident should the signal be
put to danger too soon after the train has passed and this I effect by the use of the
apparatus hereinafter described which apparatus prevents the signal lever from being
fully put back or brought to its normal or danger position though the signal may be
put to danger until after the lapse of such a time as more than suffices to enable the
passing train to pass over those parts of the line controlled by the signal.
The apparatus constituting my invention is constructed as follows:-Fixed prefer-
ably to the floor of the signalman's cabin and in front of the signal lever is a closed
hollow cylinder with a piston and piston rod the piston rod passing through a stuffing
box on the top of the cylinder. The cylinder is filled with a liquid which will not
freeze such as oil or glycerine. The piston is perforated with a series of holes all of
which excepting one or two are provided on the underside of the piston with flaps or

page_text: valves opening downwards. When the piston is pressed down in its cylinder it can
only move slowly as the liquid on its underside can only pass through the one or two
holes without flaps to the upper side very slowly. When however the piston is raised
from the bottom to the top of the cylinder it can move rapidly as the liquid passes
from the upper to the underside of the piston through all the holes. A coiled spring
or springs acting on the head of the piston rod raises the piston to the top of its
cylinder when the piston is at liberty to move. The cylinder is fixed in an inclined
position so that when the signal lever is approaching its danger position a projection
on the said lever bears directly or nearly so on the head of the piston rod. The lever
cannot fully reach its danger position except by pressing on the end of the piston rod
and forcing the piston towards the bottom of the cylinder and this as already explained
can only take place slowly the exact time being regulated by the size of the hole or
holes in the piston through which the liquid passes on the descent of the piston and
the length of the stroke of the piston. If the signalman puts the signal to "danger
too soon the motion of the lever is arrested as it approaches the end of its stroke and
can only reach its final or danger position slowly by pressure on the lever. Or the
apparatus may be automatic that is the signal lever when loosed by the signal-man
may by the action of a weight or by the pull of the signal wire be pulled over to the
danger position but can only reach this position slowly by the action of the cylinder
and piston as already explained.
22
In place of the cylinder and piston described a collapsible air vessel with valves and
vent may be employed with like effect but I prefer the cylinder and piston.
I have described my invention only in connection with a direct signal locking
apparatus but I wish it to be understood that my invention is also applicable to signal
locking apparatus of the kind known as spring catch locking apparatus as well as to
signalling apparatus generally in which it is desirable that the motion of the lever
should be controlled in the manner herein before described. And although I have
only described my invention in its application to the main line of rails I wish it to
be understood that my invention is also applicable to sidings shuntings and crossings
and generally to all such parts of or additions to railways as are under the control
of signals.
Dated this Fourth day of Marah 1887
W. T. WHITEMAN,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Train Signalling
on Railways.
I SAMUEL TELFORD DUTTON of Marl Bank in the City of Worcester, Civil
Engineer do hereby declare the nature of my 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 consists of machinery or apparatus constructed and worked in the
manner hereinafter described by the use of which machinery or apparatus risk of
accident is avoided when by carelessness or inadvertence on the part of the signalman
or from other cause the signal lever is moved from the "safe" position to the
danger" position before the train signalled has passed all the points controlled by
the signalling apparatus.
"
In order that my invention may be the better understood I remark that according
to the ordinary method of signalling the signalman keeps the signal off, that is, holds
it in its "safe" position until the train signalled has passed through all the points
and parts of the line under the control of the signalling apparatus. Immediately he
puts back the signal lever to its "danger" position the levers working the points are
unlocked and if this unlocking is effected before the train has passed the parts which
should be locked, during the passing of the train, there is great danger of accident.
The object of my invention is to prevent the risk of accident should the signal
be put to danger too soon after the train has passed and this I effect by the use of
the apparatus hereinafter described which apparatus prevents the signal lever from
being fully put back or brought to its normal or danger position though the signal
may be put to danger until after the lapse of such a time as more than suffices
to enable the passing train to pass over those parts of the line controlled by the
signal.
The apparatus constituting my invention is constructed as follows.
Fixed preferably to the floor of the signalman's cabin and in front of the signal
lever is a closed hollow cylinder with a piston and piston rod the piston rod passing
through a stuffing box on the top of the cylinder. The cylinder is filled with a liquid
which will not freeze such as oil or glycerine. The piston is perforated with a series
of holes all of which excepting one or two are provided on the underside of the
piston with flaps or valves opening downwards. When the piston is pressed down
in its cylinder it can only move slowly as the liquid on its underside can only pass
through the one or two holes without flaps to the upper side very slowly. When
however the piston is raised from the bottom to the top of the cylinder it can move
rapidly as the liquid passes from the upper to the underside of the piston through all
the holes. A coiled spring or springs acting on the head of the piston rod raises the
piston to the top of its cylinder when the piston is at liberty to move.
The cylinder

page_text: is fixed in an inclined position so that when the signal lever is approaching its
danger position a projection on the said lever bears directly or nearly so on the
head of the piston rod. The lever cannot fully reach its danger position except by
pressing on the end of the piston rod and forcing the piston towards the bottom of
the cylinder and this as already explained can only take place slowly the exact time
being regulated by the size of the hole or holes in the piston through which the
liquid passes on the descent of the piston and the length of the stroke of the piston.
If the signalman puts the signal to "danger" too soon, the motion of the lever is
arrested as it approaches the end of its stroke and can only reach its final or danger
position slowly by pressure on the lover.
Or the apparatus may be automatic that is the signal lever when loosed by the
signal man may by the action of a weight or by the pull of the signal wire be pulled
over to the danger position but can only reach this position slowly by the action of
the cylinder and piston as already explained.
I have described my invention only in connection with a direct signal locking
apparatus but I wish it to be understood that my invention is also applicable to
signal locking apparatus of the kind known as spring catch locking apparatus as
well as to signalling apparatus generally in which it is desirable that the motion of
the lever should be controlled in the manner hereinbefore described. And although
I have only described my invention in its application to the main lines of rails I wish
it to be understood that my invention is also applicable to sidings, shuntings and
crossings and generally to all such parts of or additions to railways as are under the
control of signals.
Figure 1 of the accompanying Drawing represents in elevation partly in vertical
section train signalling apparatus constructed according to my invention applied to a
signal lever; Figures 2, 3 and 4 represent respectively a vertical section a plan and
an end elevation of a portion of the apparatus shown in Figure 1 drawn to a larger
scale; Figure 5 represents in section and Figure 6 in plan a modification of the
arrangement for raising the piston in its cylinder when at liberty to move.
I do not think it necessary to exhibit in connection with my invention the locking
apparatus of the levers as my invention may be applied to various systems but it
will be understood that in all the systems employed the locking of the point and
other levers is maintained until the signal lever controlling the points is put
completely back to its normal position.
The same letters of reference indicate the same parts in the several Figures of
the Drawing.
a is the signal lever, A being its normal or danger position; the dotted line
position marked B being the position to which the lever is put back when the signal
is put to danger to act upon my invention by which the motion of the said lever is
slowly arrested and the dotted line position marked C (Figure 1) is the position of
the lever a when the signal is put to its all right" position.
d is the closed cylinder of the apparatus attached to the floor of the signalman's
cabin in front of the signal lever a by the base plate d²; f, fare slot holes in the base
plate through which bolts are passed for adjusting the position of the apparatus on
the floor of the signalman's cabin. The said cylinder d is filled with a liquid,
preferably of the kind hereinbefore pointed out: d³ is the cylinder cover containing a
guide and also a gland or packing for the piston rod; d³ is the piston working in the
said cylinder d and d is the piston rod. The piston d' is perforated at its marginal
part with a series of holes g, g to allow the liquid to pass freely from the upper to the
lower side of the piston. The said piston has also a hole h near its middle for
the liquid to pass slowly from the lower side to the upper side of the piston. Over
the marginal holes g in the piston d³ is a leather flap or valve i opening downwards
for closing the said holes when the piston is depressed in its cylinder. By means of
the screw nut k, the piston d³ and its valve i are connected to the piston rod d*. The
piston d³ is raised or propelled upwards in the cylinder d when at liberty to move by
means of the arrangement represented in Figures 1. 2 and 3, or by the modified

page_text: arrangement represented in Figures 5 and 6. In the arrangement Figures 1. 2 and 3,
is a cross head on the piston rod the said cross head carrying the two parallel guide
rods m, m partly situated on the sockets p, p on opposite sides of the cylinder d.
Around the rods m m are coiled springs n, n the inner ends of which take abutments
against the bottoms of the sockets p, p and their outer ends against the cross head / as
best scen in Figures 2 and 3. When the piston d³ and piston rod d' are depressed in
the cylinder, the springs n, n are compressed and when the pressure is removed from
the piston rod the piston is raised in the cylinder by the expansion of the said springs.
In the arrangement Figures 5 and 6 the piston rod is hollow or tubular and has
within it a single coiled spring n², the said piston rod having a closed cap head d
against which one end of the spring takes an abutment, the other end of the spring
taking an abutment in a socket t at the bottom of the cylinder d; u is a loose guide
rod inside the spring n for supporting and preserving it straight when expanded.
The action of this arrangement is the same as that first described.
On the catch box a² of the lever a'is a nose a³ which nose presses directly on the
end of the piston rod d. A pada of moderately hard india rubber may be inserted in
the bearing face of the nose a to receive any concussion that may take place between
it and the piston rod. The top of the piston rod d may have a small roller to bear
against the pad on the lever and thereby diminish friction.
In order to prevent the nose of the lever a striking the piston rod d' in case the said
lever is thrown back carelessly the quadrant s is furnished with a second notch » for
the spring catch on the lever to engage with so as to arrest the motion of the lever a
just before it comes in contact with the projected piston rod d* as indicated in the
dotted position Figure 2. On pressing the piston into its cylinder it can only move
slowly therein as the liquid on the underside of the piston can only pass through the
single hole in the said piston but when the pressure of the nose of the lever a is
removed from the piston rod the piston is raised in its cylinder by the action of the coiled
springs or spring as before explained, the piston now moving more rapidly in its
cylinder as the liquid on the upper side of the piston is permitted to pass to the
underside through all the holes in the piston.
When the lever a is in the position indicated at C Figure 1 the signal in connection
with the lever a is in its "all right" position and the piston is at the top of its
cylinder and the piston rod d in its fully projected position as indicated in dotted lines
in Figure 2. When the signal is put to danger the lever a is moved to the position
indicated in dotted lines at B Figures and 2 but the said lever is arrested and
prevented from passing to its normal position A by the nose a³ of the said lever coming
against the projected piston rod d¹ and the lever a cannot pass to its normal position A
until by pressure on the said lever a (or by the pull of the signal wire assisted by the
weight w on the said lever) it has slowly caused the displacement of the required
quantity of liquid in the cylinder d from the lower side to the upper side of the piston
as before explained. Thus, the lever a cannot fully reach its danger or normal
position A excepting by pressing on the end of the piston rod and forcing the piston d'
towards the bottom of the cylinder and this can only take place slowly the exact time
being regulated by the size of the hole (or holes) in the piston and the stroke of the
piston rod.
My invention may be applied to various constructions of locking mechanism according
to the system of working adopted and the requirements of particular cases for securing
the points and other things controlled by the signal lever while the train having been
signalled is passing through them irrespective of the altered position of the signal
arm.
Having now particularly described and ascertained the nature of my invention and
in what manner the same is to be performed I declare that I claim as my invention of
"Improvements in machinery or apparatus for train signalling on railways."
Machinery or apparatus constructed and used substantially as hereinbefore described
and illustrated in the accompanying Drawing for arresting the motion of the signal

page_text: lever before it reaches its normal or danger position and causing the said lever slowly
to reach its full normal or danger position either by manual or automatic pressure
upon it, the levers working the points controlled by the said signal lever being locked
before and during the interval of motion referred to of the said signal lever so that a
train which has been signalled will pass all the points and parts of the line under the
control of the signal in a condition of safety although the signal arm may have been
put to danger immediately after the engine of the train has passed it substantially as
described and illustrated.
Dated this Fifteenth day of November 1887.