IMPROVEMENTS IN MEANS ÓR APPARATUS EMPLOYED IN SIGNALLING ON RAILWAYS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Charles Frederick Whitworth at
the Office of the. Commissioners of Patents, with his Petition, on the
10th June 1861.
I, CHARLES FREDERICK WHITWORTH, of Moses Gate, near Bolton, Lancashire,"
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN MEANS
ÓR APPARATUS EMPLOYED IN SIGNALLING ON RAILWAYS," to be as follows:-
The improvements have for their object the obtaining greater security from
collisions and other accidents on railways, and are especially adapted to tunnels,
cuttings, curves, crossings, or inclines, junctions, stations with obscure
approaches, or other places requiring especial warning on the approach of
trains. Levers, acted upon by a passing train through connections set the
signal apparatus to indicate "danger" to a following train. As part of the
connection to the signal apparatus, I employ a sliding bar with connections to'
a weighted lever, which has also two other connections for purposes hereafter
explained. This sliding bar is provided with notches or teeth capable when:
drawn for the signal to indicate "danger," of being held by a stop or stops.
By the release of the sliding bar, and descent of the main weight acting thereon,
the signal is set to "all right," and a barrel is wound up, and the setting of tho
signal to "danger" draws up the weighted end of the lever, where it is held by'
the stop acting on one or other of the notches of the sliding bar. By this
detention of the sliding bar and main weight lever, the two upper wires to this
weighted lever will have liberty for retraction, which, as regards the topmost
wire, is effected by the power of a lesser weight suspended from the lever of
the signal arm; the influence of this weight sets the signal to "danger,"

page_text: causes a pendulum to vibrate at the same time, and liberates the winding
chain, so as to allow the barrel to revolve in accordance with the influence of
the weight and pendulum for that purpose.
The liberty of the second or middle wire connected with the main lever
permits a hammer, when released (by the descent of a smaller hammer, after the
lapse of a certain time), to descend on the stop of the slide, which it thus liberates
from the notches. A small hammer, also when the time is up, releases a rod
connected with the centre, on which the larger hammer, above referred to, is
keyed, and then this larger hammer descending on the stop of the slide causes
the release of the main weight, which, as before said, sets the signal to "all
clear," winds up the barrel, and lifts up the hammers to be retained for their
operation, when the next train which requires protection has passed through
the tunnel or other part guarded.
The apparatus is provided with a wire connection communicating to a
distance, and capable of being acted upon by a lever or other suitable
mechanism to set the signal to "danger," when required, other than by the
passing of a train. This connection is also weighted to keep the parts suffi-
ciently tight as their normal position, whilst the connecting chain is so loose
that the sliding bar will have liberty for its perfect motion of, say, some 3 or 4
inches, unless from some detention or otherwise, it may be desirable to retain
the signal at "danger "beyond the usual time, when the lever which is to be
at the further. end of the extended wire may be used to set or keep the signal
at "danger," as may be requisite; so that in the event of any extraordinary
detention, the apparatus may be acted upon by a guard or other person of the
detained train, or otherwise, to hold the signal to "danger" for any length
of time.
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This part of
Other parts of my improvements relate to the application of apparatus in
connection with improved releasers, causing a train to ring the announcing
bell of warning at a station or junction, whether the distant signal for its
protection be indicating danger," or "all clear," at the time.
my Invention also embraces the peculiar application of a crank lever,
which has the effect of retarding the too rapid motion of the vane or signal
arm of a semaphore, and causing it to be truly set to "danger," with an appli-
cation of much less power and no injurious concussion or rebound by that
excess of weight and speed, checked suddenly by an iron bracket or other stop,
sometimes producing so severe a concussion as to demolish the red glass of the
lamp, an event, which happening in the night especially, may be of very serious
consequence. These objects I propose to effect by the following means, which
will also ensure that the distant signal be set to "danger" by any train as it

page_text: passes the post, although from frost or other cause the main wire may be
fastened in the pulleys or otherwise.
Within a short distance, say, some 4 or 5 feet of the releaser, near the signal
post, I erect a short post with a weighted lever thereon; this I call the bell
or main lever, because when one arm thereof is released, as herein-after referred
to, it will, by drawing the main wire back from the station, cause the an-
nouncing bell to ring. This arm of the lever, at a short distance from its end,
is bent suddenly back, almost to right angles, towards the releaser, and the
end of this part is connected to the slide by means of a chain long enough to
allow the slide sufficient motion to permit the signal to indicate "danger"
when this arm is retained in a vertical position. Near this end of the arm
there are also two plates so connected at one end of them as to form a flat-
tened link; this link, which connects the bell lever to the main wire, and is
arranged to work on a pin, which passing through the lever, has a plate of
the link on each side of it. One end of this pin forms a stud or stay pin pro-
jecting towards the post. Near the other end of the link there is another pin,
forming in like manner a stud pin; this pin passes through a collar placed
between the flat sides of the link to keep them properly apart, when the stud
is made fast by means of a nut on one side of the plates, and a fast collar on
the other. Through the arm of this lever there is also a pin so fixed above
the plates of the link as to keep the last-mentioned stud (which I call No. 2)
from ascending within, say, about half an inch of the range of the other stud
(which I call No. 1). Below the range of these studs a pall so works on a
centre pin or stud projecting from the post as to form a stop for one or other
of the studs (1 and 2), as the signal may be set to indicate "all clear," or
danger;" and under the lower and heavier end of the pall a cam, which is.
fixed on a drum or pulley wheel, operates so as by upward pressure to cause-
the other end of the pall to descend from contact with the studs, and thus
release the lever arm, which then acts on the main wire and rings the an-
nouncing bell as required. The drum or pulley wheel on which the cam is
fixed is connected to the slide of the releaser by a chain acting over it, and
also by another reverse chain it is connected vertically to a small weighted
lever acting on a centre near the top of the post. The slide of the releaser
has two notches in it whose intermediate space accords with the motion
required by the short arm of the weighted lever on the signal post as the vane
ascends from "all clear" to "danger." The effect of the vertical reversing
chain will be a tendency to draw the cam from contact with the pall, but the
chain connection with the slide of the releaser is to be so adjusted that when
the signal indicates "all clear," the stop being in the first notch of the slide,
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page_text: "
then only will the cam have no contact with the pall; when the signal is at
danger," the stop being in the second notch of the slide, this chain will have
become tight, and have drawn the cam so as to release the pin 1 from the pall;
and on a further release from the second notch in the slidė this chain will
draw the highest part of the cam under the pall, so as to cause a release from
the second stud also. Whenever the signal is either set to "danger" from the
junction, or the slide is drawn towards, but not up to the stop, for "all clear,"
the stop catch, which is keyed on the shaft of the treddle, will rise into the
second notch of the slide, but the slide will be released from this stop by a
depression of the treddle from any passing carriage, and then by the action of
the cam on the pall the lever of the main wire will be released, also causing
the announcing bell to ring at the station or junction. The effect of a due
arrangement of the two stud pins, say, about 9 inches apart, on the link of the
main lever, as above described, with the adjustment of the 2 notches in the
slide according with the motion of the post or signal lever, will also enable the
signal-man to know at all times whether the distant signal be indicating "all
clear or "danger," with the bell apparatus set only, oven if he cannot see the
arm or light, for it will be evident from the above that when the signal is at
"danger the bell lever can only be stayed on the second stud, and conse-
quently the wire will be much further-drawn back from him and the wheel
lever, by which he operates on the signal, setting it to "danger" or "all clear"
as required, will stand in a different position altogether when at " danger
than when the signal is drawn to "all clear." In using one slide only with
2 notches therein the release from the second notch, in causing a further
motion of the signal, would derange its indications, but to prevent this I would
cause a small crank, fixed on the signal post, to act on the connecting rod
which ascends to the lever working the signal arm. This crank must be so
arranged that when the signal indicates "danger," its lever arm, which is
joined to the connecting rod of the signal, shall have descended almost to its
extreme limit of notion downwards; then its second or further motion being
under its centre to the corresponding part of the circle, it will follow that,
whether the slide be retained by the stops being in the second notch or released
altogether, the indications of the signal will be the same. The other arm of
this crank will be connected with the weighted lever of the signal by means of
a short flat rod, which must be so adjusted on the levers which it connects as
to obtain the required motion of the signal arm. But at some places it may
be desirable for trains to ring the announcing bell some 400 or 500 yards
before they arrive at the distant signal. For this, instead of a second notch
in the slide, as above suggested, I affix a second releaser at that distance with

page_text: its treddle and its weighted lever sufficient to draw back a wire extending and
joined to the main wire a few yards beyond the main weight. From this
extended wire there is also a branch wire some 10 or 12 feet long connected
to that chain, which, when the signal goes to "danger," draws the cam in
contact with the pall and releases the main lever from the first stud. The
extended wire and the branch from it are so relatively adjusted as to length
that when the further releaser liberates its weight the branch wire has liberty
to draw the chain acting on the cam so as to release the stud pin which
retains the bell weight, and thus cause the bell to ring at the junction, so that
the signal-man, having notice of the approach of a train, may draw the signal,
if at "danger," to "all clear." In drawing the main wire for this purpose ho
will also draw the extended wire, and thus he will at the same time reset the
further releaser in due position to be operated upon by the next train. For a
self-acting warning bell at crossings on the level and other places where there
are no men stationed, I use a modification of the notched bar and pendulum
apparatus above suggested for tunnels, but this, instead of setting a signal
behind the train, is to bring a part or parts of the apparatus in connection
with a wire extending forward to the part protected, which connection will
induce an electric or magnetic current to ring a bell at the place continuously
until, from the effect of a reaction of the pendulum apparatus or other means
of disconnection, the current shall again be suspended.