IMPROVEMENTS IN SIGNAL APPARATUS FOR RAILWAYS
Year: 1858

page_text: LETTERS PATENT to Charles Frederick Whitworth, of Sheffield, in the
County of York, Engineer, for the Invention of "IMPROVEMENTS IN
SIGNAL APPARATUS FOR RAILWAYS."
Sealed the 30th September 1858, and dated the 7th April 1858.
PROVISIONAL SPECIFICATION left by the said Charles Frederick Whit-
worth at the Office of the Commissioners of Patents, with his Petition,
on the 7th April 1858.
I, CHARLES FREDERICK WHITWORTH, of Sheffield, in the County of York,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE.
MENTS IN SIGNAL APPARATUS FOR RAILWAYS," to be as follows:-
The improvements relate to means for actuating signal apparatus,indicating
danger, or otherwise, by the passing of one carriage or train of carriages to
others, as also for indicating the approach or passing of other carriages or
trains. For this purpose the signal is acted upon (in preference) by a weight
with a tendency to draw the same to indicate danger, &c., and there is a wire,
chain, or other like operating connection to a windlass or other apparatus by
which the signal may be drawn to iudicate "all clear;" when thus drawn, the
end of a lever arm weighted for the purpose rises into or against a recess or
stop in a sliding plate forming part of the connecting means to the signal, to
hold that signal in that position of "all clear." The weighted lever arm is

page_text: affixed on an axis passing under the rails, and this axis has another arm rising
by the side of one of the rails, which forms an inclined plane for the flanges of
the wheels to press on, and at such time to release the sliding plate and set the
signal to danger. There are also two shorter and somewhat curved arms on
an axis in a stationary bearing above the sliding plate; these are capable of
being forced by a pin in the sliding plate, which pushes the weighted lever
arm out of the way of the notch or stop in the sliding plate when the danger
signal is required for shunting or otherwise, and there is also another pro-
jection or ledge on the sliding plate by which, these short arms are acted
upon to release the weighted lever arm and admit of its being again in
position to act upon the sliding bar; the weighted lever arm is somewhat
recessed or bent where the short levers rest on it.
In some cases it is desirable to substitute for the curved short arms a small
friction roller, so affixed to the sliding plate as to press down the weighted
lever arm and release it from the notch when the danger signal may be
required for shunting, &c. In this case the weighted end of the lever will
require a stay catch to fall underneath and retain it in position (out of the
way of the slide) until the notch in the slide has passed that end of the lever,
which would otherwise stop the slide. In the motion of the sliding plate the
stay catch is removed by the pressure of a pin or stud fixed in that sliding
plate, when the weighted lever will resume its place in contact with the slide,
and so as to be ready to take into the notch therein. In connection with the
releasing apparatus thus arranged, I also apply a bell or other alarm, to
indicate the proximity of a carriage or train of carriages. And, in connection
with the setting of a distant signal to danger, I apply a cam or tappet to raise
a lever or inclined surface to act upon apparatus carried by the locomotive
engine or tender, or other carriage if desired, of a train to release a striker,
which then, by the action of spring or weight, strikes and explodes detonating
or other such powder placed in position for that purpose. I prefer, in order to
.set the striker in position for again operating, that the engine be required to
stop, and that the position of the striker be indicated at the side of the engine
for the information of the station masters or others, so that the apparatus
may operate as a tell-tale against the driver as well as a special indication
of danger.
The striker may also be of very great service as an alarm, even when
explosive compounds are not employed, from the force of concussion exerted
by it on the platform or some suitable projection therefrom, and the sound
or vibration thereby produced.

page_text: This part of the improvements may also be brought into operation by
an inclined plane or other suitable projection or surface at other positions,
as for instance, where the road may be under repair, &c.
In some cases, with ordinary 'signal apparatus the violent sudden motion
of the signal arms to the point indicating danger breaks the glasses of the
lantern and disarranges other of the parts.
Now another part of these improvements consists in the application of an air
chamber or elastic cushion to check the violence of the motion of these arms.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Frederick Whitworth in the Great Seal Patent
Office on the 7th October 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FREDERICK WHITWORTH, of Sheffield, in the County of York, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of April, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Frederick Whitworth, Her special licence, that I, the said
Charles Frederick Whitworth, my executors, administrators, and assigns,
or such others as I, the said Charles Frederick Whitworth, my 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 SIGNAL APPARATUS FOR RAILWAYS,"
upon the condition (amongst others) that I, the said Charles Frederick
Whitworth, my executors or administrators, by an instrument in writing
under my, 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 Palent.
.
NOW KNOW YE, that I, the said Charles Frederick Whitworth, do
hereby declare the nature of the 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 thereof, that is to say:—
Theimprovements relate to means for actuating signal apparatus, indicating
danger or otherwise by the passing of one carriage or train of carriages to
others, as also for indicating the approach or passing of other carriages or
trains. For this purpose the signal is acted upon (in preference) by a weight
with a tendency to draw the same to indicate danger, &c., and there is a wire,
chain, or other like operating connection to a windlass or other apparatus by
which the signal may be drawn to indicate "all clear;" when thus drawn,
the end of a lever arm weighted for the purpose rises into or against a recess
or stop in a sliding bar or plate forming part of the connecting means to the
signal, to hold that signal in that position of "all clear." The weighted lever
arm is affixed on an axis passing under the rails, and this axis has another
arm rising by the side of one of the rails,.which forms an incline plane for the
flanges of the wheels to press on, and at such time to release the sliding bar
or plate and set the signal to danger. There are also two shorter and
somewhat curved arms on an axis in a stationary bearing above the sliding
bar or plate; these are capable of being forced by a pin in and projecting
from the sliding bar or plate, which pushes the weighted lever arm out of
the way of the notch or stop in the sliding bar or plate when the danger
signal is required for shunting or otherwise, and there is also another pro-
jection or ledge on the sliding bar or plate, by which these short arms are
acted upon to release the weighted lever arm and admit of its being again
in position to act upon the sliding bar or plate. The weighted lever arm
is somewhat recessed. or bent where the short levers rest on it.
In some cases it is desirable to substitute for the curved short arms a small
friction roller, so affixed to the sliding bar or plate as to press down the
weighted lever arm and release it from the notch when the danger signal may
be required for shunting, &c. In this case the weighted end of the lever will
require a stay catch to fall underneath and retain it in position (out of the
way of the slide) until the notch in the slide has passed that end of the lever
which would otherwise stop the slide. In the motion of the sliding bar or
plate the stay catch is removed by the pressure of a pin or stud fixed in that
sliding bar or plate, when the weighted lever will resume its place in contact
with the slide, and so as to be ready to take into the notch therein. In
connection with releasing apparatus thus arranged, I also apply a bell or other
alarum to indicate the proximity of a carriage or train of carriages. And, in
connection with the setting of a distant signal to danger, I apply a cam or

page_text: tappet to raise a lever or inclined surface to act upon apparatus carried by
the locomotive engine or tender, or other carriage if desired, of a train to
release a striker, which then, by the action of spring or weight, strikes and
explodes detonating or other such powder placed in position for that purposo.
I prefer, in order to set the striker in position for again operating, that the
engine be required to stop, and that the position of the striker be indicated
at the side of the engine or other carriage for the information of the station
master or others, so that the apparatus may operate as a tell-tale against
the driver as well as a special indication of danger.
The striker may also be of very great service as an alarum, even when
explosive compounds are not employed, from the force of concussion exerted
by it on the platform or some suitable projection therefrom, and the sound
or vibration thereby produced.
This part of the improvements may also be brought into operation by an
inclined plane or other suitable projection or surface at other positions,,as
for instance, where the road may be under repair, &c.
In some cases, with ordinary signal apparatus the violent sudden motion
of the signal arms to the point indicating danger breaks the glasses of the
lantern and disarranges other of the parts..
Now another part of these improvements consists in the application of an air
chamber or elastic cushion to check the violence of the motion of these arms.
But that the nature of these my improvements and the means I adopt
in carrying the same into effect may be fully understood, I will proceed to
describe the Drawings annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1,shews a side view of parts arranged according to one part of my
improvements, and supposed to be placed along the side of a line of railway;
and Figure 2 is a section of some of the parts; Figures 3 and 4 show some
of the parts shown by Figures 1 and 2, in other positions which they assume.
a indicates one of the ordinary rails of the railway; b is a signal post provided
with suitable signal apparatus, capable of being operated by a rod.c, as is well
understood. The upper part of this post, with an arrangement of signal
apparatus thereto such as I have employed, is represented at Figure 5, but I
do not confine myself to any particular arrangement of signal means, as such
may be varied. The upper end of the rod c, as shown, is connected by pin
joints to the lever arm d, affixed to the axis d', upon which is also affixed the
board or day danger signal (indicated by dotted lines in Figure 5) in order

page_text: that such may be moved as required. And this axis dis also provided
with another arm d², connected to the lamps, for effecting the desired
changes to them for night signals.
.
The lower end of this rod c is attached by pin joints to the weighted end of
the lever arm which turns upon a fixed axis f', and at its other end is
connected to the chain g which passes down under the guide pulley g¹, and is
then, by means of a suitable wire or band g², connected to one end of the
sliding bar or plate h, whose other end is, by another wire and chain or band
93, connected to the drum of the windlass i. The weight f' on the lever f
has a tendency to draw the signal apparatus into the position to indicate
danger," and the action of the windlass i in drawing the parts into the
position indicated by Figure 1 is to indicate "all clear," and when so'drawn
they are held by the upper end of the lever arm j rising into the notch h³,
formed in the under side of the sliding bar or plate h, to act as a stop to that
bar or plate. The lever arm is affixed upon the axis j¹, and has a weight
applied to the other end 2, acting with a tendency to bear the end; towards
the sliding bar or plate h. There is also affixed upon the axis ¹ another arm
(shewn by dotted lines in some of the Figures, and separately at Figures
5 and 5b,) inclining upwards by the side of one of the rails in position
for the upper end thereof to be depressed by the flanges of the wheels of a
passing carriage; thus, supposing the parts to have been in position shewn by
Figure 1, or that indicating "all clear," upon the passing of a carriage or
train of carriages to depress the lever arm, the upper end of the lever arm j
will be drawn down from the sliding bar or plate h, as indicated by Figure 3 ;
and as that bar h will be free to move, the weight få will act upon the rod c to
cause the indication of "danger." In order again to set the signals to indi-
cate "all clear," and so that it may be efficient for the passing of another
train, it will simply be necessary to draw the sliding bar or plate h, by the
windlass i or other suitable means, far enough for the upper end of the lever j
again to take into the notch h¹ in the under side of the sliding bar or plate h,
by which the operator will feel the addition of the check weight, indicating
that he has drawn the bar far enough for this purpose. The windlass or
other means employed for operating upon the sliding bar or plate h may be
situated at a very considerable distance; and when from any cause it may be
desirable to set the signal to indicate "danger," by releasing the slide h
without acting upon the lever arm, this may be accomplished by the wind-
lass or other means for drawing the sliding bar or plate h being caused to act
upon that bar or plate to pull it till the pius h projecting therefrom will, by

page_text: coming against the short levers k, bring them into a position for their lower
ends to act upon and depress the upper end of the lever arm j, as indicated
by Figure 4, in which position it will be held, to admit of the notch in the.
sliding bar or plate h passing the upper and outer end of the lever arm j, so
that the weight fr may draw the signals to indicate "danger." The sliding
bar or plate h is also provided with ribs h³, ha, which so soon as the notch h¹
has passed over the upper and outer end of the lever armi, come against the
under surfaces of the inner projections of the arms (shown more clearly
by the separate views of one of these levers at Figure 5), to cause them to
turn upon their centre of motion /², as indicated by dotted lines in Figure 4,
when the lever, will be again free to act upon the sliding bar or plate h, as
indicated by dotted lines in Figure 3.
Figures 6 and 7 shew by side and end views, a modification of the sliding
bar or plate h and parts acting therewith. In this case, in place of the short
curved arms k, which are brought into use when it is desired to set distant
signals to indicate danger, by the windlass or other means acting, in place
thereof I employ a small friction roller l, which when the slide h is drawn into
the position indicated by Figure 8, acts upon the lever arm j to depress it,
when the weighted end j thereof will be caught by the stop m' of the lever m
and there held till in the traverse back of the rod 7, the truck or roller n
carried by the bar or plate will, by acting on the upper end of the lever arm
m, release the stop m¹ from the end of the army, when the lever arm j will
again be in position to take into the notch ' of the sliding bar or plate h.
o is a bell suspended from the spring o¹, which is affixed to one end of the
lever o² which turns upon a fixed centre of motion 03, and at its other end
carries by pin joint the catch o', which is so placed that when the windlass
handle is turned in the direction indicated by the arrow, the short arm o
affixed upon the axis of that windlass handle simply causes that catch o' to
turn upon its centre of motion; but when upon the releasing of the sliding
rod from the end of the lever j the windlass handle is caused to revolve in the
opposite direction the short arm 05 will, in acting upon the catch 04, cause the
lever arm o² to be suddenly acted upon to ring the bell o; but in place of a
bello other alarm apparatus may be employed. For single lines of railway,
or where the trains have to run in both directions at different times on the
same pair of rails, with signal and alarm apparatus adapted to both directions
of working, it is desirable that that releasing apparatus thereto be capable of
being operated alone which corresponds with the direction in which a train may
for the time be running. For this purpose I apply apparatus, such as shown by

page_text: Figure 17, where A is a bar supported upon the upper ends of arms B and C,
and in position to be acted upon by the wheels of a passing carriage, and these
arms are placed somewhat at an angle to facilitate the action of the wheels
when the carriage or carriages to act thereon are passing in the direction of
the arrow D; the lower end of the arm B turns upon a fixed centre B¹,
the lower end of the arm C is affixed to an axis C¹. E is another bar corre-
sponding with the bar A, and intended to be alone operated by the wheels
of a carriage passing in the opposite direction, or that of the arrow F.
The bar E is supported upon the upper end of the arms G, H. The
arm G at its lower end turns upon a pin G³, the arm H is fixed to the axis H'.
In order that so soon as the bar A is depressed the bar E may be taken out
of the way of being acted upon, there is an arm C³ affixed to the axis C¹, to
the lower end of which is attached one end of the link I, the other end of
which is formed with a slot by which it takes hold of the pin H' in the arm
H³ affixed to the axis H¹ by which when the bar A is depressed the bar E
will, by the difference in the points of connection of the bar I with the
two arms, be quickly thrown over into the position indicated by dotted lines,
and a corresponding effect will take place upon the bar A when the train,
by proceeding in the opposite direction, first acts on the bar E, in which case
the effect will be communicated by the rod J corresponding with the rod I.
In order that the bars A or E may be kept down during the passing of a
train, there is another bar K capable of being acted upon by several wheels of
a train at the same time, and which is supported by pin joints upon the upper
ends of levers K', K', which are affixed to axes K2, K2, and at their other
ends are by slotted rods connected to the arms L, L, respectively affixed one
on the axis C and the other to the axis H. Upon each axis K² is also
affixed an arm. K³, to the upper end of each of which is connected one end of
a chain M, the other end of each of which is connected a weight K* capable
of bringing the parts respectively into their position for action after the passago
of a carriage or train of carriages. These chains M are also the means I
employ of connection to the respective releasing apparatus, each being con-
nected by one of its links to the upper end of an arm N affixed on an axis J¹
of releasing apparatus, such as referred to; and in some cases I apply a bell
or other alarm apparatus at a distant station in connection with the signal
apparatus to indicate to such distant station that the train has passed the
releasing apparatus of the station to which it is applied. And I prefer that
the connecting means from the releasing apparatus of the distant alarum
be of the electro-galvanic character.

page_text: In setting a distant signal to indicate danger, I also in some cases apply
means by which to act upon apparatus carried by a locomotive or other
railway carriage to cause an explosion of detonating or other suitable
powder; or it may be simply to effect a blow or produce a percussive sound
to attract the attention of the engine driver or other person in charge of such
engine or other carriage. For this purpose I apply a lever or such inclined
surface (as shown by Figures 9 and 10) capable of being raised into
position to act upon parts carried by the locomotive or other carriage, and
capable of turning upon a fixed centre p', whilst it is raised into the position
for operating by a cam or tappet p³ affixed upon an axis 24, upon which
(as shown by Figure 14) is also affixed an arm p³, the outer end of which
is connected to one end of a rod po, the other end of which is beut and formed
with an eye to embrace the screw rod p7 forming part of the chain g in
such manner that that eye may have play thereon, the distance of play being
regulated by the adjustable nuts p³, ps, by which motion will be given to
the signal apparatus, as explained.
The inclined plane p is when raised, as indicated by Figures 9 and 10), in
position to act upon the lower end of the lever arm q, which turns upon a
centre of motion q' carried by the engine, which also carries the lever q²,
whose lower end is in position to be acted upon by the upper or short end of
the lever q. is a hammer or striker, which is capable of turning upon an
axis, and is acted upon by a powerful spring with a tendency to cause
the hammer or striker r to strike at a point s, but which when set for action
is held back by resting on the turned-over end q³ of the lever q³, but so soon
as in the motion of the engine or other carriage having the apparatus applied
to it along the line, the lower end of the lever q comes in contact with the
inclined plane formed by the lever p, that lever q will be caused to turn upon
its centre q, and act upon the lever q², so that the upper end q3 of that lever
q3 will release its hold of the hammer or striker to admit of the spring 2
acting thereon to cause that hammer violently to strike at s, where I prefer
to place a case of detonating or other like explosive powder. The incline p
may on its upper surface have a series of short pieces of whalebone or other
such projection inserted therein, sufficiently flexible to give way when in
contact with hard substances, aud yet unyielding enough to ensure the
required action upon the lever q.
2
Figures 15 and 16 show an arrangement of parts adapted to operate upon
a lever 2, or such like apparatus, for effecting signals on a passing carriage,
and suitable to be temporarily applied to any portion of a line of railway to

page_text: protect parts where repairs or other operations may require indications to be
made. p is a lever acting upon a centre of motion p¹ carried by the frame u,
which is capable of being affixed temporarily to the sleepers or other parts of
the line of railway. This frame u also carries standards u¹ to support an
axis u, upon which is affixed the arm p³, as also a lever u³ for operating the
same. The axis u may also be provided with a flag or other means of
signalling ut.
In Figure 1, as also at Figures 11, 12, 13, and 14, I have also shewn
means for checking the too violent motion of the signal arms. t is an elastic
bag or case, connected with the apparatus for operating the signal arms in
such manner that in causing them to indicate "all clear," the bag may
become filled with air through a suitable valve t¹ (Figures 11, 12, and 13),
and then when the parts are released for raising the signal arm to indicate
danger, this valve will be closed, and the air therein will operate as an elastic
cushion to prevent the sudden bounding of the signal arm into the position
indicating "danger," whilst the air will also be permitted to escape by being
forced out of a small orifice t. In place of employing a valve t', the air may
be caused to flow both in and out by the same orifice of size sufficient to
admit of the bag gradually filling. The moving part of the bag t is, by means
of the link t4, connected to the outer end of arms t5, whose other ends turn
upon an axis to carried by the lever f. There are two arms t5, one on each
side of the lever f, by which that end of the lever raised will, by pushing
against the parts at t' cause the bag to be compressed whilst it admits of that
end of the lever f being lowered without pulling the link t4 with it; t8 is a
stop. If desired, a whistle may be applied to the exit passage from the
chamber to give an audible indication that the apparatus is in action and
signal duly set as the train passes it
Figures 11 and 12 shew arrangements of bag adapted more especially to
where the signalling is effected by causing the signal arms or discs to turn
with the post supporting them upon a centre to make the desired indication.
Having thus described the nature of my said Invention, and in what manner
I carry the same into effect, I would have it understood that I do not confine
myself to the precise details shown and described, as these may be varied, so
long as the peculiar characteristic of any part thereof be retained; but what
I do claim is,-
First, the mode of arranging, combining, and operating parts, substantially
as described in respect of Figures 1, 2, 3, 4, 6, 7, and 8.
Secondly, I claim the mode of arranging, combining, and operating

page_text: parts, substantially as explained in respect of Figures 9 & 10, 14, 15,
and 16.
Thirdly, I claim the mode of arranging,combining, and operating parts, for
the purpose substantially as explained in respect of Figures 1, 11, 12, 13,
and 14.
In witness whereof, I, the said Charles Frederick Whitworth, have
hereunto set my hand and seal, this Fifth day of October, in the year
of our Lord One thousand eight hundred and fifty-eight.
10 Witness,
W. BROOKES,
73, Chancery Lane, London,
Patent Agent.
C. F. WHITWORTH. (L.S.)