IMPROVEMENTS IN THE MEANS OR MODE
Year: 1867

page_text: LETTERS PATENT to. Marmaduke Wilkin, of 2, Saint James' Terrace,
Harrow Road, Paddington, in the County of Middlesex, Gentleman,
and John Clark, of 3, Orchard Street, Paddington, in the said County,
Engineer, for the Invention of "IMPROVEMENTS IN THE MEANS OR MODE OF
Sealed the 15th April 1868, and dated the 17th October 1867.
PROVISIONAL SPECIFICATION left by the said Marmaduke Wilkin
and John Clark at the Office of the Commissioners of Patents, with
their Petition, on the 17th October 1867.
We, MARMADUKE WILKIN, of 2, Saint James' Terrace, Harrow Road,
Paddington, in the County of Middlesex, Gentleman, and JOHN CLARK, of 3,
Orchard Street, Paddington, in the said County, Engineer, do hereby declare
the nature of the said Invention. for "IMPROVEMENTS IN THE MEANS OR MODE
OF SIGNALLING UPON RAILWAYS," to be as follows:-
The Invention comprehends,―
1st. Certain apparatus for depositing on the rails fog or similar detonating
signals from the last carriage or van of a train whilst the train is in motion.
2nd. The erecting and working of signal posts or indicators along the line,

page_text: so that when a train has passed the first signal post the line will remain
"blocked" until the said train shall have arrived at the second signal post,
when automatic apparatus shall clear the first section of line and the second
section be in turn "blocked," and so on to the end of the journey.
3rd. To effect the same object as the preceding, but by an interval of time
instead of distance.
4th. To deposit and remove fog or similar detonating signals at a certain
distance from a station when the usual distance signal is temporarily
obscured.
We now proceed to describe the several improvements and the means for
carrying the same into effect :-
1st. To deposit fog signals on the rails while the train is in motion. We
propose to fix the fog signal in the centre of an oblong piece of sheet lead,
tin, zinc, iron, or the like, or cardboard, or things of a similar kind, through
which slits are cut near the centre and the cut portions turned up, and into
which the signal is fitted, when the said cut portions or tongues are then bent
down to clip the signal and keep it secure. An inclined shoot is fitted to the
end of the van or carriage being the last of the train, so as to overlap the
rail whereon the tin, iron, cardboard, or other substitute prepared as above
described is laid; it then descends the incline by gravity, and is gently
transferred to the rail from the shoot. The edges of the tin, iron, cardboard,
and the like are bent downwards to enable the signal carrier to keep its
position on the rail for the short distance it will necessarily travel by the
momentum it has acquired.
We
2nd. In erecting signal posts or indicators at certain distances, say from 3
to 5 miles along the line; so that the train in passing the first signal shall keep
the line "blocked" until it has arrived at the second and so on.
propose
to erect signal posts about 14 feet high, and near the top of the said posts we
fit two horizontal boards or signals which are made to turn on their axes to
shew the line clear," or "blocked," as the case may be: Dependant from
12
and fixed to the signal board is a short lever or arm in such a position that
à corresponding ärm or guide rail fitted to the train shall' while passing throw
the said signal lever upwards to nearly right angles to its normal position, and
thus from its relative position with reference to the signal board indicate that
the line is "blocked." The said signal lever drops into a catch, and' is perma-
nently held in its position until relieved by the action of an armature of an
electro-magnet which pulls the catch back on a current being sent back from
the signal next in advance. The signal board and lever are so weighted that

page_text: on the catch being removed they assume their normal position, shewing the
line "clear" by their gravitating weight. The whole of the above-described
mechanism is constructed as light as possible consistent with its requirements.
We propose to carry in the van or other part of the train a galvanic or other
battery in connection with a vertical rod or wire which is free to swing back-"
wards. This rod projects upwards from the roof of the van or other part of
the train, and comes into electric contact with a wire which is laid diagonally
across the line. We prefer it diagonally so that the rapid motion of the train
may not strike it abruptly. When the electric contact of the two wires is
made the current is sent back to the last signal passed, which current operating
the electro-magnet and armature there the catch already described is pulled
and the signal board shews that portion of the line "clear." This same
arrangement may also be used to transmit a message in advance of the train
for the purpose of warning the persons in charge of level crossings, stations,
and the like of the approach of a train. By a slight modification it may
likewise be the means for receiving a signal from a station in advance that the
said station is "blocked" or otherwise, such as during fogs when the ordinary
distance signal is obscured.
3rd. In signalling at stated distances along the line wherein an interval of
time instead of an interval of distance is adopted. We propose to substitute for
the electric apparatus above described a chamber containing non-volatile liquid.
Into this chamber is introduced a smaller vessel having a very
small aperture
in it. When a train passes it the action of the wheels upon a suitable rail
plunges the smaller vessel into the said liquid, and from the interval which it
requires to empty itself by the small aperture described depends the time the
signal shews the line to be "blocked." It is not proposed to light these
auxiliary self-acting signals during night, but to so place the light on the front
of the engine as to exhibit them to the driver on passing them. They are
placed not far above his level, and we propose that the signal boards should be
gilded to be more visible at night.
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I 4th. To deposit on the rail, and when necessary to remove fog or other
detonating signals which are used when the usual distance signal is obscured.
We propose to fit a vertical case about two feet from the side of the rail. A
sliding lever or bar is free to move in a slide through the bottom of the case;
this lever is worked by a wire line and hand lever from the station either in
conjunction with or separate from the "distance signal." When the hand
lever is over at "clear" the sliding bar in the case is withdrawn clear of the
bottom of the case and the fog signals drop into the recess. When the harid

page_text: lever is pulled to "danger" the bar is made to advance and pushes the under-
most fog signal before it until it deposits it upon the rail, or upon a pre-
pared seat on the rail to receive it; and when it is necessary to clear the
fog signal the same movement is continued and the bar thrust a little farther,
when the fog signal drops into a receptacle inside the rail and the bar recedes
to its normal position or "all clear."
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Marmaduke Wilkin and John Clark in the Great Seal
Patent Office on the 17th April 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, MARMADUKE
WILKIN, of 2, St. James' Terrace, Harrow Road, Paddington, in the County
of Middlesex, Gentleman, and JOHN CLARK, of 3, Orchard Street, Paddington,
in the said County, Engineer; send greeting.
day of
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the
in the year of our Lord One
thousand eight bundred and sixty- , in the thirty-second year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said.
Marmaduke Wilkin and John Clark, Her special licence that we, the said
Marmaduke Wilkin and John Clark, our executors, administrators, and
assigns, or such others as we, the said Marmaduke Wilkin and John
Clark, our executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MEANS OR MODE OF SIGNALLING UPON RAILWAYS," upon the condition
(amongst others) that we, the said Marmaduke Wilkin and John Clark, our
executors or administrators, by an instrument in writing under our, or their,
or one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Marmaduke Wilkin and John Clark,
do bereby declare the nature of our said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This Invention comprises,-
1stly. Certain apparatus for depositing on the rails fog or similar detonating
siguals from the last carriage or van of a train whilst the train is in motion.
2ndly. The erecting and working of signal posts or indicators along the
line, so that when a train has passed the first signal post the line will remain
blocked till the said train shall have arrived at the second signal post, when
automatic apparatus shall clear the first section of line and the second section
be in turn blocked, and so on to the end of the journey.
3rdly. To effect the same object as the preceding, but by an interval of
time instead of distance.
4thly. To deposit and remove fog or similar detonating signals at a
certain distance from a station when the usual distance signal is temporarily
obscured.
We now proceed to describe the several improvements and the means for
carrying the same into effect, and 1st, to deposit fog signals on the rail while
the train is in motion. We propose to fix the fog signal in the centre of an
oblong piece of sheet lead, tin, zinc, iron, or the like, or cardboard or things
of a similar kind, through which slits are cut near the centre, and the cut
portions turned up, and into which the signal is fitted, when the said cut
signal and keep it secure.
portions or tongues are then bent down to dip the
An inclined shoot is fitted to the end of the van or carriage being the last of
the train, so as to overlap the rail whereon the tin, iron, cardboard, or other
substitute prepared as afore described is laid. It then descends the incline
by gravity, and is gently transferred to the rail from the shoot. The edges of
the tin, iron, cardboard, and the like are bent downwards to enable the
signal carrier to keep its position on the rail for the short distance it will
necessarily travel by the momentum it has acquired.
2nd. In erecting signal posts or indicators at certain distances, say from three to
five miles, along the line, so that the train in passing the first signal shall keep
the line blocked until it has arrived at the second, and so on.
We purpose to
erect signal posts about fourteen feet high, and near the top of the said posts
we fit the horizontal boards or signals which are made to turn on their axis to
shew the line clear or "blocked," as may be. Pendent from and fixed to
the signal board is a short lever or arin in such a position that a corre-
sponding arm or guide rail fitted to the train shall while passing throw the
said signal lever upwards to nearly right angles to its normal position, and

page_text: thus from its relative position with reference to the signal board indicate that
the line is "blocked." The said signal lever drops into a catch, and is per-
manently held in its position till releived by the action of an armature of an
electro-magnet, which pulls the catch back on a current being sent back
from the signal next in advance. The signal board and lever are so weighted
that on the catch being removed they assume their normal position, shewing
the line "clear" by their gravitating weight. The whole of the above-
described mechanism is constructed as light as possible consistent with its
requirements. We propose to carry in the van or other part of the train a
galvanic or other battery in connection with a vertical rod or wire which is
free to swing backwards. This rod projects upwards from the roof of the van
or other part of the train, and comes into electric contact with a wire which
is laid diagonally across the line. We prefer it diagonally so that the rapid
motion of the train may not strike it abruptly. When the electric contact of
the two wires is made the current is sent back to the last signal passed, which
current operating the electro-magnet and armature there the catch already
described is pulled, and the signal shows that portion of the line "clear."
This same arrangement may also be used to transmit a message in advance of
the train for the purpose of warning the persons in charge of level crossings,
stations, and the like, of the approach of a train, and by a slight modification
it may likewise be the means for receiving a signal from a station in
advance that the said station is "blocked" or otherwise, such as during fogs
when the ordinary distance signal is obscured.
3rdly. In signalling at stated distances along the line wherein an interval
of time instead of an interval of distance is adopted. We propose to substitute
for the electric apparatus above described a chamber containing non-volatile
liquid. Into this chamber is introduced a smaller vessel having a very small
aperture in it. When a train passes it the action of the wheels upon a
suitable rail plunges the smaller vessel into the liquid, and from the interval
which its requires to empty itself by the small aperture described depends the
time the signal shows the line to be "blocked." It is not proposed to light
these auxilliary self-acting signals during night, but to so place the light on
the froint of the engine as to exhibit them to the driver on passing them
They are placed not far above his level, and we propose that the signal boards
should be gilded to be more visible at night.
4th. To deposit on the rail and when necessary remove fog or other
detonating signals which are used when the usual distance signal is obscured.
We propose to fit a vertical case about two feet from the side of the rail. A

page_text: sliding lever or bar is free to move in a slide through the bottom of the case;
this lever is worked by a wire line and hand lever from the station either in
conjunction with or separate from the distance signal. When the hand lever is
over at "clear" the bar in the case is withdrawn clear of the bottom of the
case and the fog signals drop into the recess; when the hand lever is pulled
to "danger" the bar is made to advance and pushes the undermost fog signal
before it till it deposits it upon the rail or upon a prepared seat on the rail
to receive it, and when it is necessary to clean the fog signal the same
movement is continued and the bar thrust a little farther when the fog signal
drops into à receptacle inside the rail and the bar recedes to its normal position
or "all clear."
The accompanying Drawing is intended to illustrate the means whereby the
said Invention is to be carried into effect in practice.
EXPLANATION OF THE DRAWING.
Fig. 1 represents an oblong piece of sheet iron or other metal turned with
tongues, and with a fog signal fixed in the said tongues; the plates may have
tongues cut so as to receive one or more of such fog signals as required.
Fig. 2 represents the end of a goods' van with the shoot herein-before
mentioned fixed thereto. We propose also to have the shoot detached and
portable, so that the guard may step down on the foot board and reach the
rail by holding the shoot in his hand. In this case the plate with the signal
attached would be retained at the top of the shoot by spring which the
guard would release when he had the shoot in the proper position on the
rail to slip the carrying plate down thereon; a hand or other lamp can
be easily connected with the said shoot to enable the guard to ascertain
at night or in a dark tunnel whether the plate is properly deposited.
a
Fig. 3 shows an end elevation of a carriage to work signals placed along
the rail, say, at a distance of three miles apart. We fit on the side of the
carriage a longitudinal rail which may be folded up when not required;
when the said rail glides upon the lever a it elevates the signal arm b, which
is held in its horizontal position by the armature c dropping into a detent in
the joint d; when the carriage has reached the next signal post in advance a
current of electricity from the battery e in the carriage is passed along a con-
ducting wire line and operates in its circuit the electro-magnet f, which pulls
the armature c out of the detent and thus the signal arm drops. The current
may be either communicated to the conducting wire by the guide rail, or by
an independent vertical rod, as herein-before explained. The battery e in the

page_text: carriage is of the ordinary description of constant battery, but to effect a
connection with the earth more certainly we fix a vertical sliding rod inside
a tube or a piece of iron jointed and fixed to the framing of the carriage in
such position that the point shall rest upon the axle or boss of the wheel; a
direct metallic contact is thus established with the earth instead of passing
the current through the axle box as heretofore. This arrangement is also
applicable for other purposes for signalling throughout a train by electricity
.or galvanism.
Figs. 4 and 5 are two elevations, at right angles to each other, of a self-
acting signal to indicate for a certain time (instead of distance) after a train
has past a signal post. A is a horizontal bar or lever which is depressed a
short distance by the several wheels of a train, each depression causing a catch
or pawl to raise tooth by tooth a ratchet or rack near the bottom of the rod b
connected with the signal arm; the rack may contain twenty or any number
of teeth, so that when twenty wheels have passed over the bar a the arm is
elevated to shew the line "blocked." The bottom of the rack is plain so that
any greater number of wheels may pass without operating further on the
signal arm; when the rod 6 is raised it carries round the pinion C in
gear
with a toothed rack; tbis pinion is fitted with a spring catch so that it does
not move the train of wheel work in its upward movement, but the catch
caused it to lock with the toothed wheel d in its descent. C and are parts of
a train of wheelwork which retards the descent of the signal arm to any
specified time. e is a small block or drag to retard the descent more
effectively, or the highest speed spindle may be fitted with a fan to retard its
revolutions, but we prefer the drag as shewn underneath the bar a. A spring
is fitted to keep it elevated to its proper position, and when the bar is not
depressed the spring raises it sufficiently high for the pawl (f) to keep clear
of the rack and allow the descent of the rod (b).
Figure 6 is an elevation of the tube and bar to lay and remove fog signals
upon and from the rail. At a point near the ordinary distance signal outside
the station we erect a tube having a groove in two of its sides near the outside
of the line of rails. Into the said tube we drop several fog signals, and under-
neath it we fit a sliding bar A, having a recess at its end to receive one of the
signals. When the line is "clear" the bar is drawn back so that the said
recess stands under the pile of fog signals in the tube; when the line is to be
blocked the bar is pushed forward on the plate b, and one fog signal remains
in the recess which is carried close to the edge of the rail, as shewn in the
Drawing. If a wheel is run over the signal in this position it will explode

page_text: it and give notice to the driver that the station is blocked; this is intended
for use when the ordinary distance signal is obscured by fog. The bar a may
be operated by the ordinary distances signal lever, or by a lever specially
fitted for that purpose, the connection being made at the joint C.
In witness whereof, I, the said John Clark, on behalf of myself and
the said Marmaduke Wilkin, have hereunto set my hand and seal,
this Seventeenth day of April, in the year of our Lord One thousand
eight hundred and sixty-eight.
JOHN CLARK. (L.S.)