IMPROVEMENTS IN SIGNALLING APPARATUS FOR RAILWAYS, AND IN THE MODE OR METHOD OF APPLYING AND WORKING THE SAME
Year: 1876

page_text: LETTERS PATENT to Stenhouse Bairnsfather, Gentleman, and Richard Robert
Harper, Electric Telegraph Engineer, both of No. 19, Salisbury Street, Strand,
London, and 3, York Buildings, Dale St., Liverpool, for the Invention of
"IMPROVEMENTS IN SIGNALLING APPARATUS FOR RAILWAYS, AND IN THE MODE
OR METHOD OF APPLYING AND WORKING THE SAME."
Sealed the 27th June 1876, and dated the 1st January 1876.
PROVISIONAL SPECIFICATION left by the said Stenhouse Bairnsfather and
Richard Robert Harper at the Office of the Commissioners of Patents, on the
1st January 1876..
STENHOUSE BAIRNSFATHER, Gentleman, and RICHARD ROBERT HARPER, Electric
Telegraph Engineer, both of No. 19, Salisbury Street, Strand, London, and 3, York
Buildings, Dale St., Liverpool. "IMPROVEMENTS IN SIGNALLING APPARATUS FOR
RAILWAYS, AND IN THE MODE OR METHOD OF APPLYING AND WORKING THE
SAME
"
"
The first part of this Invention relates to a contrivance or contrivances fitted
or applied to distant or other signals, by which an audible signal is given to the
driver or guards, or to both the driver and the guards of a railway train, should
the train run past such apparatus when the signal is against the driver or in the
danger" position, so that in case of a sudden fog or his not observing the signal,
the driver is duly warned. The said apparatus may be placed at any convenient
position or distance in advance of the signal to be observed. For this purpose we
place upon the engine and in the guard's van a bell, gong, or other suitable con-
trivance for audibly signalling, and such apparatus is connected by a lever, rod, or
cord, which is in like manner attached to the engine. We prefer to apply it to the
engine in such a position that upon the engine coming up to and in contact with
a rigid projection (which is fitted or applied to and connected with the semaphore
or other signal) a lifting or canting action is produced upon a lever or detent,
which immediately calls the bell, gong, or other audible signal into action. This
contrivance may be applied to the guards' vans, preferably in front and rear of the
van diagonally, so that one or other would be called into action according to the
direction in which the van is travelling. We prefer putting the apparatus con-
nected with the signal close to the left-hand rail, and by the side thereof.
In some cases we prefer employing a moveable treadle (to be brought in and out
of action) which makes electric contact at such distant signal, and which will call

page_text: a bell, gong, or other contrivance into action at a signal station in advance, and
will thereby warn a signalman that a train or engine is waiting at or has run past
the signal in connection therewith.
The second portion of our Invention relates to a novel contrivance applied to or
interposed between the signal lever and the semaphore or other signal for the
purpose of ensuring and rendering more reliable the control of railway signals from
a distance by making and breaking the connection between a signal and the hand
lever employed to move it, so that the movement of the said lever can be rendered
active or inactive for the time upon the signal, as desired, from a distant station.
This we effect by interposing or applying between and in connection with the
signal lever and the wire or rod leading to the semaphore 'or other signal a frame
or platform or other arrangement of the apparatus, in connection with which is
mounted or applied the tail piece of a cranked lever (or levers), to which in turn is
connected a click tumbler piece or pieces, each working freely upon a centre, the
face of one end of each click or tumbler piece resting upon and against a tail piece
of the cranked lever; the movement of the tail piece is given by the armature or
armatures of an electro-magnet or magnets; the shorter or opposite end of each
click or tumbler piece takes into a ratchet tooth, or groove recessed within a
travelling bar and secures it, the action being as follows:-Upon the hand lever
on the signal frame being moved and the electro-magnet being inactive, then the
frame or platform travels with the movement of the hand lever, and the signal can
then be lowered. Should the electro-magnet, however, become active by the
passage of a current of electricity whilst such hand lever is pulled over, the click or
tumbler piece being acted upon by the armature or armatures, the one end of the
signal wire or rod attached to the bar with the ratchet tooth, notch, or groove
recesses is freed, and separates from the platform or frame, and thereupon the click
or tumbler piece working upon its centre is canted, and so releases the bar in con-
nection with the signal wire; the signal thereupon by reason of its counterbalance
weight at the post rises to the position of danger. Thus, by way of illustration,
take a main line with 3 signals, or signal cabins A, B, and C, at a distance apart.
A train leaving A, going towards B, the signalman at A should place his signal at
danger in rear of and to protect the train, and at the same time he should notify
on his block signalling telegraph instruments to signal box B of the approach of the
train towards B; upon which being done the signalman at B transmits a signal
to A and takes "train on line," the current passing at the same time through the
electro-magnet in connection with such apparatus by local or direct electro-magnetic
action, and the signalman at A cannot lower his signal until the train arrives at B,
or should A not have placed his signal at danger, the transmission of the current
from B in taking "train on line" will so place it self-actingly. Should there be an
obstruction on the line at C from any cause, then the action before described is
repeated, in respect of B, from station Č.
In connection with the moveable platform or frame before referred to we mount
insulated springs, such springs being in connection with the electro-magnets, the
vibrating ends of the springs resting on fixed metallic bars or bearing pieces; and,
for the purpose of economising and preventing waste of battery power at the end of
the said fixed metallic bars, we there place a piece or pieces of ebonite, so that the
action is as follows:-The signal being placed at "danger," the springs in con-
nection with the electro-magnets are resting on the ebonite and no current can pass.
Now should the lever be pulled over, contact being made on the before-mentioned
bars, the electro-magnets will then be brought into action by circuit being made,
and render the movement of the lever inactive upon the signal. This apparatus
may be applied to any other form of signal actuating apparatus than the hand lever
arrangement herein-before described.
The third portion of our Invention relates to a novel contrivance fitted and
applied to and to be used in connection with the first portion of our Invention, and
is intended chiefly, but not exclusively, for the purpose of controlling the distant
signal wire in connection with such apparatus, and consists of a drum, wheel, or

page_text: other suitable contrivance fitted and attached to the hand lever, and connected
thereto by an axle passing through the lever and the drum, wheel, or other con-
trivance. And upon the face of the drum, wheel, or other similar contrivance we
mount a frame or other attachment having cams with grippers, so that upon the
lever being moved they grip the periphery of the wheel, and travel therewith
through a limited arc of a circle. To the one end of the wire or chain which is
fixed to and wound round a drum, wheel, or other similar contrivance is attached a
weight, the wire or chain from the distant signal being in like manner attached and
wound round the drum in a contrary direction,
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Stenhouse Bairnsfather and Richard Robert Harper in the Great Seal
Patent Office on the 30th June 1876.
STENHOUSE BAIRNSFATHER, Gentleman, and RICHARD ROBERT HARPER, Electric
Telegraph Engineer, both of No. 19, Salisbury Street, Strand, London, and 3,
York Buildings, Dale Street, Liverpool. "IMPROVEMENTS IN SIGNALLING APPARATUS
FOR RAILWAYS, AND IN THE MODE OR METHOD OF APPLYING AND WORKING THE
SAME."
"
The first part of this Invention relates to a contrivance or contrivances fitted or
applied to distant or other signals by which an audible signal is given to the driver
or guards, or to both the driver and the guards of a railway train, should the train
danger
run past such apparatus when the signal is against the driver or in the "
position, so that in case of a sudden fog or his not observing the signal the driver is
duly warned. The said apparatus may be placed at any convenient position or
distance in advance of the signal to be observed, and we employ an electric
repeater, such as described in the Specification of R. R. Harper, No. 336/7, to
shew in the signal cabin the position of the fixed projection, treadle, or other
contrivance between the rails, thus assuring the signalman as to its correct working,
and this repeater will also shew the position of the distant signal arm in connection
therewith, or with such other apparatus. For this purpose we place upon the
engine and in the guard's van a bell, gong, or other suitable contrivance for audibly
signalling, and such apparatus is connected by a lever, rod, or cord, which is in like
manner attached to the engine. We prefer to apply it to the engine in such a
position that upon the engine coming up to and in contact with a rigid projection
(which is fitted or applied to and connected with the semaphore or other signal) a
lifting or canting action is produced upon a lever or detent, which immediately calls
the bell, gong, or other audible signal into action. This contrivance may be applied
to the guards' van in front and rear of the van diagonally, so that one or other
would be called into action, according to the direction in which the van is travelling
when putting the apparatus connected with the signal close to the left-hand rail
and by the side thereof; or the apparatus mounted on the road for the purpose of
calling such machinery or apparatus into action may be fitted in the centre, equi-
distant between the rails (instead of by the side, as previously described).
In some cases we prefer employing a moveable treadle (to be brought in and out
of action with the movement of the distant signal) which makes electric contact at
such distant signal, and which will call a bell, gong, or other contrivance into action
at a signal station in advance, and will thereby warn a signalman that a train or
engine is waiting at or has run past the signal in connection therewith.
The second portion of our Invention relates to a novel contrivance applied to or
interposed between the signal lever and the semaphore or other signal for the
purpose of ensuring and rendering more reliable the control of railway signals from
a distance by making and breaking the connection between a signal and the band
lever employed to move it, so that the movement of the said lever can be rendered

page_text: active or inactive for the time upon the signal, as may be desired, from a distant
station. This we effect by interposing or applying between and in connection with
the signal lever and the wire or rod leading to the semaphore or other signal a
frame or platform, or other arrangement of the apparatus, in connection with which
is mounted or applied the tail piece of a cranked lever (or levers) to which, in turn,
is connected a click tumbler, or pieces, each working freely upon a centre, the
face of one end of each click or tumbler piece resting upon and against a tail piece
of the cranked lever or combined bent levers or calliper like arrangement. The
movement of the tail piece is given by the armature or armatures of an electro-
magnet or magnets, and the shorter or opposite and of each click or tumbler piecé
takes into a ratchet tooth or groove, or mechanical equivalent) recessed within a
travelling bar and secures it. The action of the apparatus is as follows:-Upon
the hand lever, in connection with the signal being moved, the frame or platform
travels with the movement of the hand lever, and the electro-magnet being inactive
the signal can then be lowered. Should the electro-magnet, however, become active
by the passage of a current of electricity whilst such hand lever is pulled over, the
click or tumbler piece working upon its centre, being acted upon by the armature
or armatures, is canted, and so releases the bar or slide piece in connection with the
signal wire, the one end of the signal wire or rod attached to the bar with the
ratchet tooth, notch, or groove recesses is freed and separates from the platform or
frame, and thereupon the signal, by reason of its counterbalance weight at the post,
illustration, take a line with 3 signals or signal cabins A, B, and C, each at a
distance apart. A train leaving A, going towards B, the signalman at A should
place his signal at "danger," in rear of, and to protect the train, and at the same
time he should notify on his block signalling telegraph instruments to signal box B
of the approach of the train towards B, upon which being done the signalman at
B transmits a signal to A and takes "train on line," the current passing at the same
time through the electro-magnet in connection with such apparatus as herein
described by local or direct electro-magnetic action, and the signalman at A, after
such signal has been transmitted, cannot lower his signal until permission is given
him by the signalman at B, which should be done upon the train arriving and
being clear at B, and should A not have placed his signal at " danger
the
transmission of the current from B in taking "train on line" will so place it self-
actingly. Should there be an obstruction on the line at C from any cause then the
action before described is repeated in respect of B from station C.
In connection with the moveable platform or frame of the apparatus before referred
to we mount insulated springs, such springs being in connection with the electro-
magnets, the vibrating ends of the springs resting on fixed metallic plates, bars, or
bearing pieces, and for the purpose of economising and preventing waste of battery
power at the end of the said fixed metallic bars we then place a piece or pieces of
ebonite, so that the action is as follows:-The signal being placed at "danger," the
springs in connection with the electro-magnets are resting on the ebonite, and no
current can pass between the bars or metallic connections and the electro-magnet.
Now should the lever be pulled over, contact being made on the before-mentioned
bars or plates; the electro-magnets will then be brought into action by circuit being
completed and render the movement of the lever inactive upon the signal. This
apparatus may be applied to any other form of signal actuating apparatus than the
hand lever apparatus herein-before described.
The third portion of our Invention relates to a novel contrivance fitted and
applied to and to be used in connection with the first portion of our Invention, and
is intended chiefly but not exclusively for the purpose of controlling the distant
signal wire in connection with such apparatus, and consists of a drum, wheel, or
other contrivance fitted and attached to the hand lever, and connected thereto by

page_text: an axle passing through the lever and the drum, wheel, or other contrivance, and
upon the face of the drum, wheel, or other similar contrivance we mount a frame
or other attachment having cams with grippers, so that upon the lever being moved
they grip the periphery of the wheel and travel therewith through a limited arc of
a circle. These cams or grippers are removed from their attachment with the
periphery of the wheel by coming in contact with a fixed stop or other projection
when the lever is put back to its position of "clear," as shown in the Drawing.
To the one end of the wire or chain which is fixed to and wound round a drum,
wheel, or other similar contrivance is attached a weight, the wire or chain from the
distant signal being in like manner attached and wound round the drum in a
contrary direction.
<<
For the purpose of ensuring the more correct working of the semaphore or othe
home signal, and in order to prevent the signal being self-actingly placed to the
'danger" position in the face of the driver of a train, which is at all times a source
of great danger in railway working, we employ a treadle or other suitable
contrivance in connection with a contact spring or springs which are brought into
action by the engine passing over the treadle or other contrivance, thereby
completing the circuit of the before-mentioned apparatus, and the signal is thus
prevented from going to the "danger" position after the train is taken "
by the signalman at station A until the engine itself passes the signal.
on line "
In order to render this portion of the apparatus complete and effective in the case
of the signalman at B wishing to block the line "back" (as it is termed) at (A), we
employ, in addition to the commutator usually employed in train signalling instru-
ments, a spring and contact piece (or springs and contact piece), which are brought
into contact each time the commutator or other portion of the signalling apparatus
is used; and this portion of our Invention is specially designed for single line
working, and whereby the signalman at B would not only block the line at A, but
will also disconnect his own signal outside the signal cabin, causing it to assume
the danger position, thereby blocking the line between B and A; thus, should he
block the line behind a down train, he would in so doing cause his own up signal
to assume the "danger" position, and so block the line against an up train, and vice
vers. These springs and contact pieces effect the same result in relation to this
part of our apparatus as the treadle contacts, and are brought into use under the
following conditions:-Upon the signalman at B wishing to block the down line
at A, say, in the case of an up train getting off the road and fouling the down line,
or for shunting operations, or from any other cause which has occurred after the
line had been previously cleared from B to A, he (at B) would place his block
signalling instrument to the danger position, and give the requisite number of beats
on the bell or gong to station A. Upon signalman at A replying to B's line block
signal, contact is made at A by means of these springs and contact pieces, and the
semaphore arm or other home signal outside the signal cabin at A immediately
assumes the danger position; and although contact is made at A each time the
block signalling instrument is used, this portion of the apparatus is only effective
by relay, needle, or miniature semaphore arm, as previously described, while the
block instrument is at the position of danger or line blocked. Thus it will be
observed that although the signalman at B cannot place the signal at A to the
danger position he can so set the apparatus as to be effective immediately upon the
signalman at A replying to such signal, and the signalman at A, after such signal
has been transmitted, cannot place his signal to the "all right" position until the
signalman at B again restores his block signalling instrument to "line clear."
In some cases we prefer employing a miniature semaphore disc or other visual
signal in a prominent position outside the signal cabin, to be worked in conjunction
with the home signals, and having an electro-magnet in addition to those described
for actuating the before-mentioned apparatus, and which is brought into use under
the following circumstances:-The line being clear and the signals for the par-
ticular line being placed to "clear," upon the approach of a train and its being.
taken on by the signalman at B, a current is made to pass through the. electro-

page_text: magnet, which thereupon holds the platform by an armature in connection with
the before-mentioned apparatus, and thereby prevents the signalman at A from
placing the miniature signal to "danger," but he is enabled to place his home signal
to "danger" (and in the case of a stopping train he should do so); the driver of a
train by means of the miniature signal outside the cabin is thus assured the line is
olear to B, as the miniature arm or other signal does not go to the danger position
until the driver runs over the treadle [arrangement before described, and after
passing over such treadle or its equivalent the miniature is placed to the "danger
position; it cannot be then lowered without the permission of the signalman at B.
This arrangement can also be applied for blocking the line, as previously described,
as applied in connection with the home signal.
"
For the purpose of providing greater safety in the working of long and through
sidings, where such sidings are used for clearing the main line of a slow train to
make way for a fast one, and in order to prevent the signalman after admitting the
slow train to the siding forgetting the position of such train and letting in a second
train to work through, we use and employ that portion of the Invention for discon-
necting, and so placing the siding signal to the position of "danger," by the train
passing over the treadle arrangement soon after entering the points, and after such
train has entered the siding the siding signal cannot be again lowered for a second
train until after the starting signal has been cleared to allow the passage of the first
train out through the trailing points on to the main line.
In connection with this portion of our Invention we prefer employing a relay or
a needle arrangement, as described in the Specification of R. R. Harper, No. 336,
1875, in which, when a current of electricity passes through the electro-magnet,
the armatures remain magnetized inductively, and the position of the needle or
miniature arm remains unalterable until a reversal of the current takes place, and
the same action and operation is reversed.
In the accompanying two Sheets of Drawings we have shown some of the modes
in which we propose to apply the several portions of our Invention in practice, and
though in some of the illustrations we have given only one view of such apparatus,
the different positions which the moveable parts assume are indicated by firm and
dotted lines respectively.
In Sheet 1, Figure 1 shows a side view of a rail and an elevation of distant
signal post with a weighted lever and gear for working the signal; also, the
actuating apparatus mounted between the rails for calling into action the alarm
eignal on the engine, tender, or guard's van, or either of them; and it also shows
the arrangement of weighted lever for throwing in and out of action the obstruction
which sets the alarm signal or signals on the train in motion.
Figure 2 is a novel arrangement of alarm bell mechanism which is called into
action after passing over the obstruction, suitably placed, as before mentioned, by
the side of or between the rails, and which alarm signal is self-actingly set by the
vertically sliding rod, and its rack being forced upwards and rotating the wheel into
which it gears, which carries a paul or click which slips over the ratchet wheel in
rising, and takes into it in falling in the course of passing over the before-mentioned
obstruction, and the bell is called into action after such obstruction is passed over,
as a vertically pendant rod becomes released and free to fall, and in falling gives
motion to the hammer stem, which gives a series of blows upon the bell or gong
until the apparatus is unwound.
Figures 3 and 4 show two views of an apparatus for compensating for the
expansion and contraction of the wires of distant and other signals, level crossing
gates, and such like purposes, as herein-before described, and the action of this
apparatus will be readily understood by reference to such Figures.
Figures 5 and 6 show a modification of the mechanical apparatus shown in
Figures 3 and 4, and in which the wheel or drum is provided with ratchet teeth;
and although this modification is shown as having two canting bits or arms, in some 5
cases it may be found more convenient to use only one of such arms.
In Sheet 2 we have illustrated two methods of applying the second portion of

page_text: our invention; and we will describe the apparatus, as shown in Figure 7, by
detailing the action. In the position in which the apparatus is shown the signal is
pulled in or cleared. Upon a current traversing the coils the armature (c) is
attracted to the poles of the coils (b); the opposite end of the armature lever gives
motion, and cants the cranked lever (d), the roller of which (e) in like manner cants
the cranked lever (f), the roller of which in turn glides over the face of the tumbler
piece (h); the bar (i) by reason of the counterweight at the signal turns over the
tumbler into the position indicated by (h¹), the result being that the signal then
assumes the "danger" position, the bolt (i) passing to the position indicated by the
dotted lines, and the tumbler piece (h) is then restored to its normal position,
shown at (h), by reason of the spiral or other reacting spring. Should the
operator attempt to pull the signal down from the position of "danger" to that of
clear, then the tumbler piece (h) is turned over by means of the end of the
bar (i) to position shown by (h). By pulling the lever over the tumbler piece
slides up the end of the bar (i), and falls into the slot therein. Now, upon again
pulling the lever over to the "clear" or "all right" position, the tumbler piece
would again assume the position of (h¹), and would continue to do so all the time
the current traverses the coils. The spring (k) is connected between the moveable
platform (a) and the box (1) containing the sliding piece, which has a notch in the
inner end, as shown, whilst the signal wire is attached to the outer end thereof, the
use of the said spring being for the purpose of overcoming the friction, and drawing
the two portions together when the hand lever is released. Instead of the spring
a counterweight chain and pulley may be employed for a like purpose.
"
Figure 8 shows a modification of Figure 7, but in this arrangement the whole of
the apparatus is placed horizontally. Upon the platform (a), and in lieu of the tail
of the lever armature, as shown in Figure 7, we employ a piston, to the one end of
which is an armature (c), and the other end terminates with a spear-shaped end
having two acting faces (c¹), but which end may in some cases be a cone; and
instead of the cranked levers (d and f, Figure 7), we employ two double-ended
levers (d) and (d) with rollers at each of the ends thereof. The sliding platform (a)
rests upon a base (a¹), and is guided by side strips (a"). Upon the armature (c)
being attracted to the coils (b) the spear-shaped end (c) is withdrawn from the
double-ended levers (d and d¹), which, by reason of the spiral spring connecting
them, are drawn together, and thereby liberate the tumbler pieces, the result being
similar to that described in Figure 7.
When employing the apparatus herein-before described for working the miniature
signals, and when an additional electro-magnet is employed, the platform and
signals being pulled to correspond to the "clear" position, the ends of the armature
(m and m) would be held by the electro-magnet placed behind the platform; and
should the electro-magnet become active the operator would be unable to let the
platform run out to place the miniature signal to the "danger" position, as the plat-
form in such a case would be connected to the home signal by a chain or its
equivalent, which would form a loop and enable the operator to pull both home,
and miniature signals "off," but prevents him from placing the miniature "on," by
reason of the loop, being formed through, or by reason of the platform being held
by the armature (m and m²). Should the coils (b) become active, the armature (c)
being attracted, the spring (n) would pass from connecting plate (o) to ebonite (p),
the result being to break the circuit in the before-mentioned electro-magnet, thereby
releasing the platform, and thus preventing waste of battery power in either
case.
Though in Figures 7 and 8 we have only shown one electro-magnet, and we have
herein-before referred to the use or employment of more than one electro-magnet,
such additional electro-magnets may be employed where a signal has to be controlled
from a number of signal cabins.
We are aware that there is nothing new in the idea of employing a treadle or
moveable curved bar by the side of or between the rails, for the purpose of acting
upon a gong, bell, or whistle, on the engine, tender, or in the guard's van by means

page_text: of a pendant lever or rod, or where the treadle or curved bar is in like manner
applied for the purpose of setting a signal and unsetting signals by the roadside,
for recording the passage of an engine or train past that particular point, and for
indicating the period of time that has elapsed from the passing of such train, and
for other such cases in connection with railway working; but whilst disclaiming its
application for any of these purposes as has heretofore been done, and for the use
and employment of such treadle, or for the shape and configuration thereof, as
shown on the accompanying Drawing, what we intend to claim in connection with
that part of our Invention is,―
First. The use or employment of such treadles or bars only in conjunction with
and for the purpose of actuating the audible signal apparatus herein described in
the manner set forth.
Second. The use or employment of such treadle when used in conjunction with
the audible signal apparatus herein described, and for the purpose of winding up
and setting the said signalling apparatus during the time the engine or guard's van
is passing over it.
Third. The use or employment of the repeater and the commutator employed in
connection therewith when actuated by the treadle arrangement, as herein
described, for the purpose of indicating in the signal cabin the position or state
of such treadle, and the apparatus connected therewith.
Fourth. We claim the arrangement, construction, and mode of working the
audible signal or bell apparatus herein described, in the manner set forth and
illustrated, by which whenever the said signal becomes necessary or is intended to
be brought into use, it is first set or wound up by being carried over such 'fixed
projection or treadle as herein described.
As to the 2nd part of our Invention we are aware that magnetic arrangements
of apparatus have heretofore been employed in conjunction with the mechanical
actuating apparatus, for working and for regulating the working of home and
distant signal apparatus of railways, and we are perfectly conversant with the
various apparatus of Farmer & Tyer, Spagnoletti, Tykes, and others who have in
various ways (essentially differing from our Invention) used or employed electro-
magnetic contrivances in combination with mechanism, for the several purposes set
forth and claimed by them; but we wish it to be understood that in connection
with the second part of our Invention we limit ourselves to the following claims in
respect thereof,-
First. The use and employment of tumbler pieces for the purpose of alternately
holding and severing the connection between the lever or its connections, and the
signal or its connections in manner described, or any mere modification thereof for
the purpose
of taking advantage of the making and breaking of the electric
contact for effecting the purposes set forth.
Second. The combination of the electro-magnetic apparatus as herein described
in conjunction with the mechanical apparatus as herein set forth for the purpose
of severing the connection between the lever and the signal, as respectively shown
by the apparatus illustrated in Figure 7, and also by the apparatus shown in
Figure 8, or any mere modification thereof.
Third. The use and employment of an additional electro-magnet in connection
with miniature signals as herein described, for the purpose of preventing the signal
being placed to the "danger" position after the train is taken " on line "
by the
signalman at a station in advance of such signal, until the front portion of the
train has passed over the treadle and acted upon the apparatus in connection
therewith or unless an obstruction signal is given on the block instrument.
Fourth. The use and employment of contact makers as herein described (in
connection with and in addition to the commutators employed for train signalling
purposes) for actuating such apparatus.
Fifth. The arrangement and disposition of the springs and contact makers as
shown in Figures 7 and 8 in connection with the moving platform, and the piston
or other equivalent arrangement attached to or actuated by the armature or

page_text: armatures as herein described, for the purpose of economising battery power in
apparatus employed for such or like purposes.
Sixth. The use or employment of the treadle contacts for actuating the apparatus
described in the second portion of our said Invention.
As to the third portion of our Invention we wish it to be understood that we
are aware of the various mechanical contrivances that have heretofore been
patented, provided, and used by Saxby, Mackenzie, Clunes and Holland, Tyer,
Prince, Beynon, and others, for a like purpose, but our Invention differs essentially
from each and every of them; and what we claim in respect of the third portion is,
the apparatus herein described and as illustrated by Figures 3, 4, 5, and 6, (Sheet 1)
for self-actingly adjusting the lengths of the signal wires of railways, and others,
long length of wires liable to expansion and contraction employed for like or
similar purposes as herein described and illustrated by the said Figures or any mere
modification thereof.
In witness whereof, I, the said Richard Robert Harper, have hereunto set my
hand and seal, this Twenty-eighth day of June, in the year of our Lord
Witness,
H. H. M. SMITH,
19, Salisbury Street,
Strand, W.C.
RICHARD ROBERT HARPER. (L.S.)