Improvements in Train-signalling Apparatus.
Year: 1892

page_text: Date of Application, 4th July, 1892
Complete Specification Left, 24th Mar., 1893-Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Train-signalling Apparatus.
I, JOSEPH SOLANGE HENRI PELLAT of 3, Avenue de l'Observatoire, Paris,
France, Lecturer of the Faculté des Sciences, Paris, do hereby declare the nature
of this invention to be as follows:-
This invention relates to improvements in train-signalling apparatus whereby
(1) A graphic record is obtained of the movements of trains whose relative
positions upon the line are automatically signalled;
(2) Signals may be transmitted to the drivers of trains, with the object of
preventing accidents.
According to my invention, the train in motion itself makes its own graphic
record by tracing dots upon a paper strip under the eye of an employé stationed at
a fixed point, who can observe the movements of the whole of the trains upon a
section of the line, say over a distance of from fifty to eighty miles upwards, at the
middle of which the employés post is situated.
The inscription of the graphic record upon the paper strip while the same is
being unwound at a uniform slow rate of, say, four millimetres per minute, may be
obtained mechanically by the employment of electro-magnets but it is preferred to
use an electro-chemical process based on the decomposition of a saline solution so
as to leave a visible trace upon the paper strip, the salt which I employ for the
purpose being iodide of potassium. The strip of unsized but slightly starched
paper is passed through a trough containing a weak solution of iodide of potassium
(say of a strength of both) with which it becomes impregnated. The paper strip
then passes over a metal faced roller communicating with the negative pole
of a battery and beneath a series of platinum points placed at equidistances apart
and each communicating by means of a wire with a treadle which on a train passing
over it puts the wire in communication with a single main wire connecting with the
positive pole of the battery whereby the circuit is momentarily established and
beneath the platinum point connected with that treadle, electro-chemical decom-
position takes place whereby a very distinct black dot is formed upon the white
paper strip as a notification to the employé of the passing of the train over that
part of the line where the treadle is situated.
Reference is to be had to the accompanying drawings, forming part of this
Specification, which illustrate various arrangements of apparatus for carrying the
invention into effect.
Figure 1 is an elevation, Figure 2 a longitudinal section, and Figure 3 a plan, of
the apparatus carrying the paper strip and platinum points.
Figure 4 is an elevation, and Figure 5 a transverse section on line 1-2, of the
treadle arrangement.
Figure 10 is a diagram shewing the electrical connections for one part of
a line.
The apparatus represented in Figures 1, 2, and 3, comprises a reel A from which
a paper strip B is unwound and led down beneath a roller D in an electro-chemical
bath contained in a trough C and thence over a metal cased drum E against which
bear the brushes or springs F connected with the negative pole of a battery P
(Figure 10) the paper strip being pressed against the drum E by a guide roller G
and springs H and then wound upon a roller I. The drum E is rotated preferably
by clockwork although it may be otherwise operated. Upon the paper strip B
where it passes over the drum E a series of platinum points J placed at equal
distances apart are caused to bear, by means of springs K attached to steel rods,
each in communication with a treadle M (see Figures 4, 5, and 10) by a separate
line wire. L. The clockwork movement which drives the drum E (Figures 1, 2,

page_text: and 3,) is caused by a simple arrangement, to pass a current, say every ten minutes,
through two platinum bars 2 (Figures 1 and 3).for tracing on the strip B, every
ten minutes, a fine black line so as to form a reference record of the times at which
the treadle contacts have been operated by the trains.
The platinum points J (Figures 1, 2, and 3) are distinguished either by figures
or letters or by colors which may be repeated at certain intervals. A particular
color may, for instance, be appropriated to the point corresponding to the treadle
nearest to the station, another special color, red for example, at the third kilometre
distant from the station, so that the employé observing the train record made
opposite the red one, may immediately signal the approach of the train to the
station.
The treadle (Figures 4 and 5) consists essentially of a bar M placed against the
inside of the rail N and supported upon an elliptic spring O mounted upon a base
plate bolted to the sleepers S. The bar M is guided by tongues T received in
grooves U of guides V which are provided with slots X in which the guide pins Y
of tongues T slide. At mid-length of bar M which inclines downwards towards
either end is fixed a plate a which is insulated from the upper half of spring O by
a plate of ebonite and from the underside of which plate project downwards two
tubes bb in which are received two telescopically-sliding contact studs cc which
are connected to the tubes by cross pins d sliding in slots e for the purpose of
raising said studs out of contact with plate g which is insulated from the lower
half of spring O by a plate of ebonite. The contact studs c c are electrically
connected by the wire coils ff to plate a and which is connected with the wire L
which by the depression of the treadle is connected with wire L' from the positive
pole of battery P when the studs c c make contact with plate g. The contact studs
are enclosed in a casing i provided with a cover j and the parts T, V, Y, etc., are
similarly enclosed in casings k provided with covers for the purpose of protection
from rain and dirt and keeping them in working order. At stations it would be
necessary to provide a treadle of considerable length (which might be considered
as a succession of treadles having a single bar M in common) to produce a contact
so long as a train remains stationary on a main line. The treadle or other
apparatus for closing the circuit on the passage of a train over certain points of the
line may be of any suitable kind, but prefer to employ one or other of the
following devices which complete the improved system of railway signalling of this
invention.
Figure 6 is an elevation and plan of a latch commutator.
Figures 7 and 8 are sectional elevations, the latter figure being taken on line 34,
of a rotating drum.
Figure 9 is an elevation and plan of a commutator without latch.
By employing a series of commutators of the kind shewn in Figures 6 and 10,
the official supervising the trains is enabled to give and repeat a warning signal
on one or several locomotives hauling trains, by using the same line wires L and a
special return wire m. The latch commutator switches the current from battery n
situated at the post of observation into a relay placed at the side of the line which
latter establishes communication between a local battery and a rotating drum
(Figures 7 and 8) with which a metallic brush on the locomotive makes contact
in passing over said drum so as to energise a Hughes electro-magnet whereby a
signal is sounded upon the locomotive, such as a prolonged whistle for example,
thus intimating to the driver the necessity of slackening speed and of keeping a
careful look-out. The metallic brush makes contact with the whole circle of the
drum, the extent of the brush surface being at least equal to the circumference of
the drum which is rotated by the brush over it so that the brush will in any event
make contact with the underside of the drum which being protected from snow
and ice good electrical contact is ensured. The drum (Figures 7 and 8) has a
metallic circumference o and is weighted at o' so as to give it a constant tendency
to return to its initial position and is mounted on an axis p journaled in standards g
rising from a base ŕ supported upon and insulated by a wood sole s from the

page_text: ground and from a metal box t fixed to the sleepers. The axis p has collars u upon
which brushes x are pressed by springs v, the brushes being connected by wire z to
one of the poles of the local battery. The device is protected from rain by a
casing y provided with an opening at top for the upper part of drum o to project
through.
In order to ensure the employé's watchfulness of the graphic strip as it unwinds,
he should be required to warn each station of the approach of a train when at a
certain distance, say three kilometres, from the station. The apparatus employed
for this purpose is similar to that previously described, that is to say by means of
one of the wires L passing the station (the return being made through the earth
wire 1) and by means of the same battery n a relay situate at the station is actuated
by a key such as represented in Figures 9 and 10 whereby the circuit of a local
battery is closed through an electric bell or other signal. The approach of an up
or down train may thus be signalled.
It will be understood that the arrangements herein described may be varied
without in any way departing from the nature of the invention which consists
essentially in a combination of elements whereby to obtain automatically at a given
point of the line a graphic record of the progress of trains travelling thereon and
also of transmitting signals to the engine drivers.
Dated this 4th day of July 1892.
J. S. H. PELLAT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Train-signalling Apparatus.
I, JOSEPH SOLANGE HENRI PELLAT of 3, Avenue de l'Observatoire, Paris,
France, Lecturer of the Faculté des Sciences, Paris, 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 improvements in train-signalling apparatus whereby
(1) A graphic record is obtained of the movements of trains whose relative
positions upon the line are automatically signalled;
(2) Signals may be transmitted to the drivers of trains, with the object of
preventing accidents.
According to my invention, the train in motion itself makes its own graphic
record by tracing dots upon a paper strip under the eye of an employé stationed at
a fixed point, who can observe the movements of the whole of the trains upon a
section of the line, say over a distance of from fifty to eighty miles and upwards, at
the middle of which the employés post is situated.
The inscription of the graphic record upon the paper strip while the same is
being unwound at a uniform slow rate of, say, four millimetres per minute, may be
obtained mechanically by the employment of electro-magnets but it is preferred to
use an electro-chemical process based on the decomposition of a saline solution so
as to leave a visible trace upon the paper strip, the salt which I employ for the
purpose being iodide of potassium. The strip of unsized but slightly starched
paper is passed through a trough containing a weak solution of iodide of potassium
(say of a strength of th) with which it becomes impregnated. The paper strip
then passes over a metal faced roller communicating with the negative pole of a
battery and beneath a series of platinum points placed at equidistances apart and
each communicating by means of a wire with a treadle which on a train passing
over it puts the wire in communication with a single main wire connecting with the
positive pole of the battery whereby the circuit is momentarily established and
beneath the platinum point connected with that treadle, electro-chemical decom-
position takes place whereby a very distinct black dot is formed upon the white

page_text: paper strip as a notification to the employé of the passing of the train over that
part of the line where the treadle is situated.
Reference is to be had to the drawings, accompanying my Provisional Specifi-
cation, which illustrate various arrangements of apparatus for carrying the invention
into effect.
Figure 1 is an elevation, Figure 2 a longitudinal section, and Figure 3 a plan, of
the apparatus carrying the paper strip and platinum points.
Figure 4 is an elevation, and Figure 5 a transverse section on line 1-2 of the
treadle arrangement.
Figure 6 is an elevation and plan of a latched key.
Figures 7 & 8 are sectional elevations, the latter figure being taken on line 3-4,
of a rotating drum.
Figure 9 is an elevation & plan of a key without latch.
Figure 10 is a diagram shewing the electrical connections for one part of a line.
The apparatus represented in Figures 1, 2, and 3, comprises a reel A from which
a paper strip B is unwound and led down beneath a roller D in an electro-chemical
bath contained in a trough C and thence over a metal cased drum E against which
bear the electrical contact brushes or springs F connected with the negative pole
of a battery P (Figure 10) the paper strip being pressed against the drum E by a
guide roller G and springs H and then wound upon a roller I. The drum E is
rotated preferably by clockwork although it may be otherwise operated. Upon
the paper strip B where it passes over the drum E a series of platinum points .J
placed at equal distances apart are caused to bear, by means of springs K attached
to steel rods, each in communication with a treadle M (see Figures 4, 5, and 10)
by a separate line wire L. The clockwork movement which drives the drum E
(Figures 1, 2, and 3,) is caused by a simple arrangement to pass a current, say
every ten minutes, through two platinum bars 2 (Figures 1 and 3) for tracing
on the strip B, every ten minutes, a fine black line so as to form a reference
record of the times at which the treadle contacts have been operated by the
trains.
The platinum points J (Figures 1, 2, and 3) are distinguished either by figures
or letters or by colors which may be repeated at certain intervals. A particular
color may, for instance, be appropriated to the point corresponding to the treadle
nearest to the station, another special color, red for example, at the third kilometre
distant from the station, so that the employé observing the train record made
opposite the red point, may immediately signal the approach of the train to the
station.
The treadle (Figures 4 and 5) consists essentially of a bar M placed against the
inside of the rail N and supported upon an elliptic spring O mounted upon a base
plate Qbolted to the sleepers S. The bar M is guided by tongues T received in
grooves U of guides V which are provided with slots X in which the guide pins Y
of tongues T slide. At mid-length of bar M which inclines downwards towards either
end is fixed a plate a which is insulated from the upper half of spring O by a plate
of ebonite and from the underside of which plate project downwards two tubes bb
in which are received two telescopically-sliding contact studs cc which are con-
nected to the tubes by cross pins d sliding in slots e for the purpose of raising said
studs out of contact with plate g which insulated from the lower half of spring O
by a plate of ebonite. The contact studs c c are electrically connected by the wire
coils to plate a which is connected with the wire L, which by the depression of
the treadle is connected with wire L' from the positive pole of battery P when the
studs c c make contact with plate g. The contact studs are enclosed in a casing
provided with a cover j and the parts T, V, Y, etc., are similarly enclosed in
casings k provided with covers 7 for the purpose of protection from rain and dirt
and keeping them in working order. At stations, it would be necessary to provide
a treadle of considerable length (which might be considered as a succession of
treadles having a single bar M in common) to produce a contact so long as a train
remains stationary on a main line.

page_text: The apparatus for signalling to the engine driver on the passage of a train over
certain points of the line may be of any suitable kind, but I prefer to employ the
following devices, illustrated in Figures 6, 7, 8. By employing a series of latched
keys, such as shewn in Figure 6, the official supervising the trains is enabled to
give and repeat a warning signal on one or several locomotives hauling trains by
using the same line wires L and a special return wire m (Figures 6 and 10). The
key switches the current from battery n situated at the post of observation into a
relay placed at the side of the line, which latter establishes communication between
a local battery and a rotating drum (Figures 7 and 8) with which a metallic brush
on the locomotive makes contact in passing over said drum so as to energize a
Hughes electro-magnet whereby a signal is sounded upon the locomotive, such as
a prolonged whistle for example, thus intimating to the driver the necessity of
slackening speed and of keeping a careful look-out. The metallic brush makes
contact with the whole circle of the drum, the extent of the brush surface being at
least equal to the circumference of the drum which is rotated by the passage of the
brush over it, so that the brush will in any event make contact with the underside
of the drum which being protected from snow and ice ensures a good electrical
contact. The drum (Figures 7 and 8) which has a metallic circumference o and
is weighted at o¹ so as to give it a constant tendency to return to its initial position,
is mounted on an axis p journaled in standards q rising from a baser supported
upon and insulated by a wood soles from the ground and from a metal box t fixed
to the sleepers. The axis p has collars u upon which brushes are pressed by
springs v, the brushes being connected by wire z to one of the poles of the local
battery. The device is protected from rain by a casing y provided with an opening
at top for the upper part of drum o to project through.
The drum may be mounted on a vertical, instead of a horizontal, axis as described,
which would admit of the drum being more completely protected from rain by an
iron hood placed above it, the part of the casing which surrounds the drum
protecting it from injury and giving passage only to the part of the drum with
which the brush is to make contact, the brush being in this case so mounted as to
project laterally and horizontally in order that it may come in contact with the
exposed part of the drum.
In order to ensure the employe's watchfulness of the graphic strip as it unwinds,
he should be required to warn each station of the approach of a train when at a
certain distance, say three kilométres, from the station. The apparatus employed
for this purpose is similar to that previously described, that is to say by means of
one of the wires L passing the station (the return being made through the earth
wire 1) and by means of the same battery (Figure 10) a relay situate at the
station is actuated by a key such as represented in Figure 9 whereby the circuit
of a local battery is closed through an electric bell or other signal. The approach
of an up or down train may thus be signalled.
It will be understood that the arrangements herein described may be varied
without in any way departing from the nature of the invention which consists
essentially in a combination of elements whereby to obtain automatically at a given
point of the line, a graphic record of the progress of trains travelling thereon and
also of transmitting signals to the engine drivers.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is―
1st. The combination of devices hereinbefore described for obtaining an auto-
matic graphic record of the progress of railway trains and indicating the exact
positions respectively occupied by said trains, substantially as hereinbefore described
and illustrated in Figures 1, 2, 3, 4, 5, and 10, of the drawings.
2nd. The recording apparatus consisting essentially of a series of platinum points
contacting with a paper strip moved by clockwork whereby on the closing of a
circuit through any one of them a graphic record in the form of a line or dots is

page_text: produced, which indicates the passing of a train over the corresponding treadle or
other circuit-closing apparatus, substantially as hereinbefore described and illus-
trated in Figures 1, 2, 3, of the drawings.
3rd. The treadle circuit closing device operated by the passing of a train as
described and illustrated more particularly in Figures 4 and 5.
4th. The rotary drum contact constructed and arranged to operate in combination
with a brush contact, substantially as described and illustrated in Figures 7 and 8.
Dated this 24th day of March 1893.
J. S. H. PELLAT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.