Improved Means for Providing Trains with Automatic Signals.
Year: 1895

page_text: Date of Application, 6th Dec., 1895
Complete Specification Left, 11th July, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improved Means for Providing Trains with Automatic Signals.
We, VINCENT LITCHFIELD RAVEN, Locomotive Engineer, and CHARLES
BAISTER, Assistant Locomotive Engineer, both of the North Eastern Railway
Works, Darlington, in the County of Durham, do hereby declare the nature of
this invention to be as follows:-
This invention relates to means for providing the engines of trains with
automatic signals.
The object in view is that when the engine arrives within a certain pre-
determined distance of the signal to be observed an alarm is automatically set
off and continues to sound until intentionally stopped by the engine driver or his
assistant who are thereby warned in all states of the weather of their approach to
the signal when at danger.
The requisite mechanism for carrying out our invention is attached in part to
the engine itself and in part is provided in permanent positions along the line at
which the alarm is intended to be given. That part of the mechanism which is
attached to and carried along with the engine consists of a steam whistle of the
usual construction furnished with a specially constructed steam valve controlled or
set off by the displacement of a pendulum lever to which it is connected by a rod
extending through the foot-plate of the engine, the pendulum lever being pivotally
attached to the under frame of the engine and extending downwards towards the
rail level or thereabouts so that the requisite displacement thereof can be effected
by any suitably contrived obstruction erected in the line of its track.
The mechanism for effecting this obstruction consists of a bar placed across a
rail track and furnished with two wing plates or their equivalents extending
radially therefrom, one of which lies in the track of the pendulum lever tail end,
whether the locomotive is going engine first or tender first. The bar is preferably
mounted on bearings so as to be capable of turning about its own axis by means
of a crank or its equivalent connected to the same tensile or the like appliance
which actuates the signal in respect of which the alarm is to be given. By this
arrangement the wing plates are set in the erect position when required to displace
the pendulum lever, that is when the signal is at danger, and are turned down out
of the way when no alarm is to be given.
The arrangement of valve for admitting steam into the whistle is specially
designed to suit the action of the rod which connects it to the pendulum lever and
consists of a circular disc valve mounted on a horizontal spindle, the said spindle
being furnished with a stuffing box and otherwise suitably fitted up to render the
valve case steam tight and the valve sufficiently sensitive. Suitable ports are
furnished in the valve and valve seat, so that when the valve is turned upon its
spindle the ports are brought opposite, and the steam in the valve chamber passes
through to the whistle. When the valve is reversed the ports are closed and the
whistle stopped. This can only be done intentionally by the engine driver or his
assistant.
But it is found in practice that the impact of a lever carried by an engine at
high speed against an obstruction placed in the line of its track is too sudden and
violent to be utilized for setting up an alarm by opening the ports of a steam
whistle unless provision is made to transmit from such impact and the excessive

page_text: energy derived therefrom a relatively steady and suitable movement of the rod
which operates the valves of the whistle.
We will therefore describe a suitable contrivance for effecting the purpose of
our invention in this respect, but we do not limit ourselves to the precise
construction of parts which may be readily varied and are given for illustration of
what is suitable and as explaining what is required.
The vertical operating rod of the whistle which we will term the valve rod is
furnished with a link or foot sletted horizontally and corresponding in position to a
plate fixed to the engine frame, and slotted anglewise or to a curve which inclines
upwards towards each terminal from its centre which is also its lowest point.
A connecting rod pivotally attached to the pendulum lever at one end is connected
at the other to the valve rod by means of a pin fitted into both the valve rod link
and the fixed slotted plate and the valve rod is restricted to a vertical movement
only by means of guides. The impact of the pendulum lever communicates a sharp
thrust to the connecting rod which drives or draws the pin along the combined
slots of the fixed plate and valve rod link and imparts a relatively small vertical
movement to the valve rod. Having in this way attained the requisite movement
of the valve rod it is utilized by furnishing the upper end thereof with a tooth or
cog like projection extending from the valve spindle. The upward movement of
the valve rod lifts this valve spindle projection out of its way and in doing so sets
off the whistle which continues to sound until the valve is reversed and closed
by hand, the valve rod having in the meantime dropped back to its normal position
by gravity.
It is also found in practice that the obstruction provided in the permanent
way in accordance with our invention should not be rigid but should yield to some
extent to the impact due to the violent displacement of the lever. This may be
effected by any suitable means such as by attaching a weight to a wheel or pulley
mounted on the end of the bar to which the wing plates or the like obstructions
are fixed. When these wing plates are raised to the vertical position from the
signal box, stop pieces or toes are brought into contact with the surface of the
permanent way and sustain the weight so that when the impact comes the obstructions
can yield by lifting the weight which at once pulls the bar round and brings them
back to the vertical position. Where a suspended weight is used for this purpose,
the weight is preferably housed in a suitable chamber, from which snow, ice or
other elements which would obstruct the free movement thereof are excluded.
is of course obvious that a device as hereinbefore described could be attached to
the guard's van except that the alarm in that case would be charged with
compressed air instead of steam, or otherwise constructed in any suitable manner.
Dated this 5th day of December 1895.
It
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Ageut for the Applicants.
We, VINCENT LITCHFIELD RAVEN, Locomotive Engineer, and CHARLES
BAISTER, Assistant Locomotive Engineer, both of the North-Eastern Railway
Works, Darlington, in the County of Durham, 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 means for providing trains with automatic signals, and
has for its object to improve the action and construction of automatic signals of
the kind in which the alarm is set off by the displacement of a pendulum lever

page_text: attached to the locomotive caused by a suitably contrived obstruction placed in the line
of its track and the result obtained is that when the engine arrives within a certain
predetermined distance of the signal to be observed an alarm is automatically set
off and continues to sound until intentionally stopped by the engine driver or his
assistant who are thereby warned in all states of the weather of their approach to
the signal in question when at danger.
In carrying out our invention we provide a system of mechanism which by means
of its construction and the combination of its several parts is adapted to transmit
to the operating mechanism of an alarm or whistle a steady and suitable movement
derived from the violent and sudden displacement of the pendulum lever when
striking the obstruction at a high speed.
The novel and essential features of our invention will be understood from the
following description taken with reference to the accompanying drawings in which
the same letters of reference are used throughout to indicate the like or corresponding
parts or details of the mechanism employed.
Fig. 1 illustrates a rear end elevation of a locomotive looking into the cabin and
bringing into view the parts of the signalling apparatus which are attached to the
locomotive, and also in contact therewith the part which occupies a fixed position
on the permanent way.
Fig. 2, is a sectional view taken on line of Fig. 1 and illustrating the
signalling apparatus as hereinafter described when used in the form of an
automatically operated steam whistle.
Fig. 3 is also a sectional view taken on line x x of Fig. 1 so far as the general
construction of the locomotive is brought into view, but showing a modified
arrangement of certain parts of the signalling apparatus by which it is adapted
for sounding the whistle by compressed air derived from the air brake.
Figs. 4 and 5 illustrate that part of the apparatus which occupies a fixed
position in the permanent way, Fig. 4 showing a view in elevation taken
crosswise to the rails, to which Fig. 5 is a corresponding view in plan.
Figs. 6 to 17 inclusive are detached views appended for the purpose of allowing
to be more easily distinguished and explained certain of the details concerned in
the proper working of the apparatus.
That part of the mechanism which is attached to and carried along with the
engine consists of a steam whistle a of the usual construction furnished with a
specially constructed steam valve which is illustrated to an enlarged scale in
Figs. 9, 10 and 11. This steam valve is controlled or set off by the displacement
of the pendulum lever b to which it is connected by a rod c extending through the
foot plate of the engine, the pendulum lever being pivotally attached to the under-
frame of the engine and extending downwards towards the rail level or thereabouts
so that the requisite displacement of the said lever can be effected by any suitably
contrived obstruction erected in the line of its track.
The mechanism for effecting this obstruction consists, as shown in Figs. 4 to 6
inclusive, of a bar d placed across the rail track and furnished with two wing plates
or their equivalents d' d' extending radially therefrom, one or other of which lies
in the track of the pendulum lever tail end according to whether the locomotive is
going engine first or tender first. The bar d is mounted on bearings so as to be
capable of turning about its own axis by means of a crank or its equivalent
connected to the same tensile or the like appliance which actuates the signal in
respect of which the alarm is to be given.
The arrangement of valve for admitting steam into the whistle a is illustrated to
an enlarged scale in Figs. 9, 10 and 11 of which Fig. 9 is a longitudinal sectional
view, and Figs. 10 and 11 are transverse sectional views taken on lines y y and z z
of Fig. 9. respectively. This valve is specially designed to suit the action of the
rod which connects it to the pendulum lever b, and consists of a circular disc valve e
mounted on a horizontal spindle f, the said spindle being furnished with a stuffing
box and otherwise suitably fitted up to render the valve case steam tight and the
valve sufficiently sensitive. Suitable ports e¹ & are furnished in the valve and

page_text: valve seat respectively, so that when the valve is turned upon its spindle the
ports are brought opposite and the steam in the valve chamber passes through to
the whistle. When the valve is reversed the ports are closed and the whistle
stopped. This can only be done intentionally by the engine driver or his
assistant.
But it is found in practice that the impact of a lever carried by an engine at a
high speed against an obstruction placed in the line of its track in the manner
intended by this invention is too sudden and violent to be utilized for setting
up an alarm by opening the ports of a steam whistle unless provision is made to
transmit from such impact and the excessive energy derived therefrom a
relatively steady and subdued movement of the rod which operates the valve of
the whistle.
We will therefore describe a suitable contrivance or combination of parts for
effecting the purpose of our invention in this respect, and which may be taken as
illustrating the essential feature thereof, but we do not limit ourselves to the
precise arrangement of parts as shown and described as these may be readily
varied and are given for illustrating what is suitable and as explaining what is
required.
The vertical operating rode of the whistle which we will term the valve rod is
furnished with a link or foot c' slotted horizontally and corresponding in position
to a plate g fixed to the engine frame and slotted anglewise or to a curve in the
manner shown in Fig. 2, that is with an incline upwards towards each terminal from
its lowest and central part. A connecting rod / pivotally attached to the pendulum
lever at one end is connected at the other to the valve rod c by means of a pin h¹
fitted as a through bolt into both the valve rod link c and the fixed slotted plate g.
The valve rod c is restricted to a vertical movement only by means of guides so that
when the impact of the pendulum lever communicates a sharp thrust to the con-
necting rod h the pin h' is driven or drawn along the combined slots of the fixed
plate and the valve rod link c' and imparts a relatively small vertical and
subdued movement to the valve rod c. Having in this way attained the
requisite reduced movement of the said valve rod it is utilized by furnishing
the upper end thereof with a tooth or cog like projection 2 which engages with
a tooth or radial projection f extending from the valve spindle f. The upward
movement of the valve rod lifts this valve spindle projection out of its way and
in doing so sets off the whistle which continues to sound until the valve is
reversed and closed by hand, the valve rod baving in the meantime dropped
back to its normal position by gravity. Fig. 3. illustrates this operating
mechanism modified and adapted to sound the whistle by air derived from the
air brake instead of by steam. In this arrangement the air is conveyed from
the air brake supply through the air valve by means of the pipe k¹. The
construction of an air valve suitable for the purpose is shown to an enlarged
scale in sectional view in Figs. 12 and 13, and the whistle is illustrated mounted
on an air jet in front elevation and part sectional view in Figs. 14 and 15
respectively. Where a
vacuum brake is used a single reed instrument is
substituted for the whistle, for which the valve and its accessories are equally
adapted. Figs. 16 and 17 illustrate to an enlarged scale a means of cushioning
the impact of the pendulum lever b with the obstruction wing d'; the tail end 6' is
pivotally attached to the pendulum rod and packed with a rubber cushion 62
which yields by compression to relieve the impact.
It is also found in practice that the obstruction provided in the permanent way
in accordance with our invention should not be rigid but should yield to some
extent to the impact due to the violent displacement of the lever. This may
be effected by any suitable means such as are shown in Figs. 4, 5 and 6 in which
a pull over weight is slung from the pulley m so as to pull against the chain or
wire n leading to the signal cabin. Figs. 7 and 8 illustrate a modified arrangement
by which the pull over weight is attached to the pulley m and the liability of
the chain to snap under the strain of a series of sudden jerks is obviated. When

page_text: the wing plates or cranks d' d¹ are raised to the vertical position from the signal
box, stop pieces or toes o are brought into contact with the surface of the
permanent way as shown in Figs. 4 and 5 and sustain the weight and prevent the
draw bar from being pulled too far over.
The weight or weighted pulley is preferably housed in a suitable chamber
from which snow, ice, or other elements which would obstruct the free movement
thereof are excluded.
It is of course obvious that a device as herein before described could be attached
to the train elsewhere than on the engine, but if far away, as for instance in the
guard's van at the rear end of the train, steam could not be conveniently used, but
compressed air would be available for sounding the whistle as when the apparatus
is attached to the engine.
Having thus described our said invention and the manner of performing the
same, we wish it to be understood that we are aware that signalling apparatus has
been devised in which the displacement of a lever pivotally attached to a train by
impact against an obstruction placed in the permanent way is the means proposed
for giving the alarm and that such a signalling apparatus cannot be broadly
claimed as novel, and we have found in practice that such apparatus is not
reliable for effecting its purpose in the absence of suitable provision as herein-
before described for reducing the sudden and violent displacement of the lever to
a steady and gentle movement in the valve rod of the whistle, but we do not limit
ourselves to the precise arrangement or combination of parts shown in the drawings
which may be obviously varied into equivalent constructions without exceeding the
scope of our invention, and what we claim is :-
1. The use and construction of automatic signals for trains of the kind in which
the alarm is set off by the displacement of a pendulum lever attached to the train
caused by a suitably contrived obstruction placed in the line of its track, the said
construction being characterized by suitable means for reducing or modifying the
sudden and violent movement of the said pendulum lever to a steady gentle
movement for operating the valve, substantially as and for the purpose as
hereinbefore described with reference to the accompanying drawings.
2. The general combination of parts constituting the apparatus as a whole,
arranged, constructed, and effecting its purpose substantially in the manner
hereinbefore described.
2012
1. 1904
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicants.