Improvements in Explosive Signalling Apparatus for Railways.
Year: 1898

page_text: Date of Application, 7th Nov., 1898
PROVISIONAL SPECIFICATION.
Improvements in Explosive Signalling Apparatus for Railways.
We, THE ELECTRIC FOG SIGNAL SYNDICATE LIMITED, of 16, Cockspur Street,
London, W., and WILLIAM ROBERT SYKES, of Station Road, High Street, Clapham,
London, S.W., Railway Signal and Telegraph Engineer, do hereby declare the
nature of this invention to be as follows:
This invention relates to electric train-operated explosive signalling apparatus
for railways and has for its object to provide an apparatus of simple and inex-
pensive construction whose operation may be made automatically dependent on
the position of the ordinary visual signals.
The apparatus comprises a gravity operated cartridge holder having successive
pairs of cartridge chambers and adapted to be brought, by step-by-step motion
of the rack under the control of an escapement, successively a pair at a time into
firing position; a gravity operated firing hammer normally held in operative
position so as when released to fall and explode the pair of cartridges for the
time being in firing position; means whereby the hammer is automatically
reset by the force of the explosion itself, consisting of a discharge receiving
device adapted to receive and apply the force of the explosion to raise the
hammer, the discharge receiver being pivoted and counterweighted and coupled
with the hammer by a strap or chain reversely wound on barrels on the axis of
the one and of the other; means of electrically controlling the fall of the
hammer so as to render the discharge dependent on the position of the visual
signal; electrical means of giving warning of failure to act; means of rendering
the discharge, and the operation of the cartridge chamber for bringing fresh
cartridges into firing position, dependent on the passage of a train, and for
adapting the apparatus for use on single lines or in situations where trains pass
in both directions on the same rails.
The cartridge holder is a chambered bar vertically guided in a suitable frame
controlled by a rack and escapement. The hammer is held raised by a latch
which is released by an electro-magnet which may be in circuit with a switch
operated by or in conjunction with the visual signal so as to be dependent
thereon, and a treadle-operated circuit closer adapted to be closed by the depres-
sion of the treadle under the front wheel of a train. The hammer in its fall
acts on an electric switch controlling the circuit of the hammer releasing magnet
and also the circuit of an escapement operating magnet in circuit with a second
treadle operated circuit closer placed at a distance along the line. The escape-
ment magnet when energized by the closure of its circuit on the second treadle
operated circuit closer, releases the escapement and permits of its oscillation
under the descent of the cartridge holder to the extent of one step, in order to
bring a fresh pair of cartridges into firing position. The oscillation of the
escapement has also for result to return the switch to the position from which
it was moved by the fall of the firing hammer, thus preparing the hammer
releasing circuit for operation again.
The operation of the escapement may, however, be controlled by a switch

page_text: whereby its operation is rendered dependent on that of the firing mechanism
or on the position of the visual signal so that the cartridge holder need not be
shifted unless a signal has been fired. At the instant of discharge the hammer
momentarily closes the circuit of an alarm bell in the signal cabin but the
hammer being instantly raised again by the force of the explosion the bell is
only sounded momentarily to shew that the apparatus has done its duty. Should
however the hammer fail to be raised by a miss-fire, the alarm will be continuous
until the apparatus is put in order. The same continuous alarm is sounded by
the closure of the circuit at the same point by a contact on the cartridge holder
in such position as to denote that it will shortly require to be re-charged and
re-set.
In order to adapt the apparatus for being worked by trains in either direction
the treadle contact maker for the escapement magnet circuit would be duplicated,
in advance and in rear of the treadle contact maker by which the firing hammer
is released, the escapement being so modified that a repeated action of the escape-
ment is necessary to effect a complete operation so that after a discharge the
apparatus will be left in an intermediate position the completion of the operation
taking place on the approach of the next train in whichever direction it may
come.
Dated this 7th day of No
1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
ways
We, THE ELECTRIC FOG SIGNAL SYNDICATE LIMITED, of 16, Cockspur Street,
London, W., and WILLIAM ROBERT SYKES, of Station Road, High Street, Clapham,
London, S.W., Railway Signal and Telegraph Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:-
This invention relates to electric train-operated explosive signalling apparatus
for railways and has for its object to provide an apparatus of simple and inex-
pensive construction whose operation may be made automatically dependent on
the position of the ordinary visual signals.
The apparatus comprises a gravity operated cartridge holder or magazine having
a series of pairs of cartridge chambers adapted to be brought, by the step-by-
step motion of a rack under the control of an escapement, successively a pair
at a time into firing position; a pair of gravity-operated firing hammers normally
held in the raised or operative position so as when released to fall and explode
the pair of cartridges for the time being in firing position; means whereby the
hammers are automatically re-set by the force of the explosion itself consisting
of a discharge receiving device adapted to receive and apply the force of the
explosion to raise the hammers the discharge receiver being pivoted and counter-
weighted and coupled with the hammers by a strap reversely wound on barrels
on the axis of the one and of the other; means of electrically controlling the
fall of the hammers so as to render the discharge dependent on the position of
the visual signal; electrical means of giving warning of failure to act; and
means of rendering the discharge, and the operation of the cartridge chamber
for bringing fresh cartridges into firing position dependent on the passage of
a train and for adapting the apparatus for use on single lines or in situations
where trains pass in both directions on the same rails.

page_text: Reference is to be had to the accompanying drawings forming part of this
specification wherein Figure 1 is a front view of the explosive signalling
apparatus, Figure being a side view (partly in section), and Figure 3 a back
view of the same. Figure 4 is a plan view of one of the switches, and Figure 5
is a diagram of the electrical connections between the apparatus and the corre-
sponding semaphore signal and the signal cabin.
The cartridge holder or magazine consists of a vertical bar A having a series
of pairs of horizontal chambers a a each adapted to contain an explosive cartridge
the holder being capable of downward movement under the influence of gravity
in vertical guides 6 in a frame B under the control of rack and escapement
mechanism hereafter described whereby the cartridges are brought successively,
a pair at a time, into position to be exploded by the firing hammers. The latter
consist of a pair of levers c¹, c, pivoted about a common horizontal axis c and
each having a weighted head C normally held raised by a latch attached to
the armature of an electro-magnet D by whose action, when excited by a current,
the latch is released for the purpose of allowing the hammers simultaneously
to descend by an angular movement about the axis c and explode the cartridges.
The pair of cartridges to be exploded, when in the firing position, are presented
each with its percussion cap centrally opposite to a hole f in the frame B, and
the discharge of each cartridge is effected by a pin F which is mounted on an
arm f hung from a centre f and is driven through hole f into the percussion
cap at the rear of the cartridge when the back of the lever is struck by the
corresponding hammer head C in its descent. The arm f¹ is pressed upon by
a spring f3 so as to normally hold the firing pin F just clear of the cartridge but
within the bell-mouthed aperture of the hole f, to which position the arm and
pin are caused to return on the recoil of the hammer by the spring f
C
Each member of the pair of hammers is independently hung, the one on the
shaft c and the other on a sleeve loose on said shaft. The fall of both hammers
is accelerated by the descent of a weight G suspended by the chain g which is
wound around the sleeve c³ so as to actuate directly the hammer mounted on
said sleeve, the weight acting upon the other hammer by the engagement of a
lug on the sleeve, with a lug g2 on the shaft c.
66
The means whereby the force of the explosion is utilized for the purpose of
automatically re-setting the hammers in firing position comprises a cylindrical
or cup-shaped bell H hung by one arm of a lever H¹ from a shaft in position
to receive the discharge from the pair of cartridges, the force of the explosion
causing the lever H to turn about its fulcrum h in the direction of the arrow
in Figure 2 until checked by the buffer spring which ensures the return of
the lever and bell to the "set" position and also (by engaging with the counter-
weighted arm of lever H') serves as a stop for the same when so returned.
On shaft is keyed a pulley H2 to whose periphery is fixed a belt which is
also attached to the periphery of a pulley I fast on the shaft c, the belt being
arranged as shewn in Figure 2 so that on the bell H being thrown upwards by
the explosion in the direction of the arrow, the belt causes the rotation of shaft e
in the direction to cause the hammers to recoil to the set position where
they are retained as before by latch d, the hammer mounted on shaft c being
actuated directly and the one mounted on sleeve being acted upon by the
engagement of lug g with lug g'. It is to be noted that when the hammers C
and bell H are in the "set" position as shewn in Figure 2, the belt h³ is just
slack enough to allow the hammers to fall freely, the slack being taken up by
the rotation of pulley I due to the fall of the hammers so that the rotation of
pulley H2 consequent on the explosion of the cartridges, at once causes a pull
to be exerted through the belt for the purpose of re-setting the hammers, the
force of whose recoil is received by a pair of springs ji which cause the hammers
to rebound until stopped and retained by the latch d. In order to ensure such
engagement of the latch with the hammers at the proper moment, the latch lever
is provided with a downwardly-projecting arm d adapted to be engaged by the

page_text: back of the hammer heads C when these reach the limit of their recoil; so that
the latch, which had been raised by the hammers as they passed to their extreme
position, is thus caused to descend into position to engage the hammers on their
rebound.
The escapement mechanism controlling the descent of the magazine A com-
prises a Y-shaped anchor escapement lever K fulcrumed at k on the frame B
of the machine and carrying on one of its upwardly directed Y-arms a pallet k¹
adapted, when lever K occupies its normal position, to engage the downwardly
directed teeth of a rack L' (whose pitch is equal to that of successive pairs of
cartridge chambers in the magazine) fixed to one side of the magazine A whose
descent is thus prevented. The other Y-arm of lever K carries a pallet
adapted to be acted upon in their descent by the upwardly directed teeth of
a rack L² (of same pitch as rack L¹) fixed to the corresponding side of the
magazine A. The tail end of lever K has a pin and slot connection at m with
the upper arm m³ of a balance lever M. fulcrumed at m² whose lower arm carries
an adjustable weight whereby the lever is caused (when free to vibrate) to
so act upon lever K that the pallet (which normally engages with a tooth of
rack L is released and permits the magazine A to descend. The lever Mis
normally prevented from so acting by the engagement of its upper arm m³ with
a spring-pressed latch n forming one arm of the armature lever of an electro-
magnet O, which when excited attracts its armature o thus releasing latch n
from lever M whose arm m³ is vibrated (by weight M¹) towards the right in
Figure 1. The tail end of lever K is consequently vibrated also towards the
right, whereby pallet is retracted from engagement with rack L. The
magazine A therefore descends, and in so doing the inclined back of the next
following tooth of rack L2 presses upon pallet and vibrates lever K, causing
the latter to return to its normal position so that pallet & engages with the next
tooth of rack L' following that from which it has just been retracted. In its
return movement lever K acts, through the pin and slot connection m, on lever M
so as to return the latter to its normal position of engagement with latch n
whereby further descent of the magazine is prevented.
It being necessary that the magazine A should descend easily in its guides
the latter are made a slack fit and in order that the exact registration of the
percussion cap (at the rear of each cartridge) with the pin hole f (in the frame B)
should not thereby be liable to be disturbed, the elbow lever l' carrying the
weight P and fulcrumed to the frame at p is caused to exert a constant pressure
by means of the roller p against one side of the cartridge holder, so steadying
the latter.
A lever Q pivoted at g to the frame B is pressed by spring q¹ against one side
of the cartridge holder A so that when the top of the latter in its descent passes
the tail of the lever (which is arranged to happen when the majority of the
cartridges have been exploded) the upper end of the lever closes, through a
contact g², an electric circuit whereby a bell RI is rung in the signal cabin (see
Figure 5) to warn the signalman that the cartridge holder or magazine A requires
replenishing. In order to save time this is preferably done, not by then refilling
the same magazine but by inserting a fresh one in the guides from above,
the new magazine descending as before by gravity into operative position. The
distance between the last pair of cartridge chambers of the old or exhausted
magazine and the first pair of chambers of the new or full magazine is equal to
that between adjacent pairs of cartridge chambers in both magazines and to
the pitch of the racks L' and L2 so that the working of the apparatus is not
interrupted by the passage from the old to the new magazine, the former of
which drops out at bottom of the guides and may be removed and refilled at
leisure.
Upon the hammer shaft c is keyed a cam R by which when the hammers fall,
the electric circuit-closing spring is permitted to touch the contact 1 thus
establishing a circuit by means of which the bell just referred to is rung in

page_text: the signal cabin to apprise the signalman of the fall of the hammers. If the
cartridges are exploded by this fall of the hammers, the bell signal thus trans-
mitted is of only momentary duration, owing to the immediate recoil of the
hammers causing cam R to at once raise spring r off contact r', but if no explosion
takes place, the bell H not being thrown up, the hammers remain also down in
firing position and the bell in the cabin continues ringing until the apparatus
has been attended to and re-set.
The means whereby the various portions of the apparatus are electrically con-
trolled and their movements co-ordinated are as follows:-the electro-magnet D
which when excited permits the fall of the firing hammers, is in circuit on the
one hand with a switch s (Figure 5) operated by or concurrently with the raising
of the visual signal or semaphore S to "danger so as to be dependent thereon,
and on the other hand with a circuit-closer t operated through a treadle T (placed
in the immediate vicinity of the apparatus) when said treadle is depressed by
the leading wheel of a passing train. The circuit is thus so far completed by
the act of raising the semaphore signal to "danger" but the cartridges are not
fired until, by the passage of a train, the circuit of magnet D controlling the
fall of the hammers is closed.
A pin on one of the firing hammers C engages in its fall with the arm u
of a three-armed lever U (Figure 4) by means whereof a switch is operated,
whereby the action of the escapement K is controlled and co-ordinated with
that of the hammers so as to effect the bringing into position of a fresh pair
of cartridges at the proper time. A second arm of lever U carries a brush U₁
which normally rests upon a contact through which and through the brush
the circuit of magnet D is normally so far completed. When however by the fall
of the hammers C the lever U is actuated, the brush U passes on to another
contact in the circuit of the escapement-controlling magnet this latter
circuit being completed and the escapement permitted to act when, by the passage
of the leading wheel of the train over a second treadle V placed at a distance
of somewhat more than a train-length (say 300 yards) in advance of the treadle T,
the circuit-closer in the circuit of magnet is operated. The consequent
vibration of the escapement lever K returns the brush U₁ to initial position,
a third arm of lever U engaging for this purpose with a block /* fixed to
lever K.
A switch W may be placed in the signal cabin as indicated in Figure 5, so as
to enable the circuits controlling the operation of the apparatus to be completed
or broken in accordance with the state of the weather or other governing condi-
tions, without the necessity of the signalman leaving his cabin.
In order to adapt the apparatus for being worked by trains running in either
direction, the treadle operated circuit-closing mechanism V for the circuit of
the escapement magnet O would merely be duplicated (as at VI, ¹, Figure 5)
in advance and in rear of the treadle-operated circuit-closing mechanism T t by
which the firing hammers are released, the second circuit-closer ¹ being connected
by a branch wire to magnet 0. It will be obvious that, as the train must pass
over and depress the treadle T before the closure of either or can cause a
current to pass through the coil of magnet O, it follows that the depression
of whichever of the treadles V or V1 is first encountered by the train will be
inoperative as regards the escapement mechanism, the circuits controlled by
both and 1 being broken at contact until after the hammers, released by
the depression of treadle T, have fallen, as previously described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. Explosive signalling apparatus for railways consisting essentially in the
combination of a gravity-operated cartridge holder or magazine; an escapement
adapted to permit of the movement of the magazine for bringing the cartridges

page_text: successively into firing position; a hammer for firing the cartridges, adapted
to be automatically re-set after operating; electrically-controlled means whereby
on the passage of a train the hammer is permitted to act; electrically-controlled
mechanism whereby the operation of the escapement is rendered dependent on
the passage of a train; and a switch so acted on by the hammer and by the
escapement as to co-ordinate their action; the whole combined and arranged for
operation substantially as specified.
2. The combination with explosive signalling apparatus for railways com-
prising a gravity-operated magazine having a series of separate chambers to
contain cartridges and a hammer for exploding said cartridges controlled by the
train, of electrically-controlled train operated escapement mechanism adapted to
permit of the cartridges being brought successively into position to be exploded,
such mechanism consisting of an anchor escapement one of whose pallets normally
engages the downwardly-directed teeth of a rack on the magazine so as to sustain
the latter whilst the other pallet is adapted to be engaged by the upwardly-
directed teeth of a second rack when the first is withdrawn so as to effect the
return of the escapement to its normal position, a gravity-operated lever coupled
to the anchor lever so as to tend to release the escapement, a latch which normally
prevents such action, and an electro-magnet whose armature when actuated
withdraws the latch from engagement with said lever said electro-magnet being
in circuit with a treadle-operated circuit-closer actuated by the train substantially
as specified.
or
3. In explosive signalling apparatus for railways wherein cartridges contained
in a gravity-operated magazine are successively brought under the control of a
train-operated escapement into position to be fired, the combination with a pivot-
ally-mounted gravity-operated firing hammer normally held in the "set"
operative position uych so as, when released, to fall and explode the cart-
ridge which for the time being is in position to be fired, of means for auto-
matically re-setting the hammer consisting of a lever rotatable about its fulcrum
by the impact of the charge when exploded, pulleys on the axes of the lever
and hammer respectively, and a band attached to the pulleys for transmitting
the motion of the lever to the hammers substantially as specified.
4. In explosive signalling apparatus for railways wherein cartridges contained
in a gravity-operated magazine are successively brought under the control of
a train-operated escapement into position to be fired, the combination with a
pivotally-mounted gravity-operated firing hammer normally held in the "set"
or operative position by a latch so as when released to fall and explode the cart-
ridge which for the time being is in position to be fired, of means for rendering
such action of the hammer dependent on the passage of a train said means con-
sisting of a treadle-operated circuit-closer in proximity to the rails and in circuit
with an electro-magnet adapted, when excited, to retract the latch from engage-
ment with the hammer substantially as specified.
5. In explosive signalling apparatus for railways the combination with escape-
ment mechanism whereby cartridges are permitted to be successively brought,
by the step-by-step movement of a gravity-operated magazine into position to
be exploded by a gravity-operated train controlled firing hammer, of means
whereby the action of said escapement is rendered dependent upon the passage
of a train, said means consisting of a treadle-operated circuit-closer in proximity
to the rails and in circuit with an electro-magnet adapted when excited to
retract a latch from engagement with a gravity-operated lever whereby the
escapement is withdrawn from engagement with the magazine substantially as
specified.
6. In explosive signalling apparatus for railways comprising a gravity-operated
cartridge holder or magazine, an escapement adapted to permit of the cartridges
being brought successively into firing position, means of rendering the release
of the escapement dependent on the passage of a train consisting of a latch which
normally retains the escapement in engagement with the magazine but is re-

page_text: tracted by an electro-magnet in circuit with a treadle-operated circuit-closer,
a pivotally-supported and gravity-operated firing hammer normally held in posi-
tion to act when released on the passage of a train by the action of an electro-
magnet in circuit with a treadle-operated circuit-closer; the combination with
the electrically-controlled releasing mechanisms of the escapement and of the
firing hammer respectively, of means for electrically co-ordinating the action
of those mechanisms consisting of a switch adapted to be actuated in the one
direction by the hammer in its fall so as to switch a current to the electro-magnet
controlling the operation of the escapement and to be actuated by the escapement
in the other direction so as to switch the current to the electro-magnet controlling
the operation of the firing hammers substantially as specified.
7. In explosive signalling apparatus for railways comprising a gravity-operated
cartridge holder or magazine and a hammer for exploding the cartridges, both
controlled by the train, the combination with the magazine of a weighted elbow
lever adapted to bear against one side of the magazine so as to hold the same
steady in its guides whilst permitting freedom of downward movement sub-
stantially as and for the purpose specified.
8. In explosive signalling apparatus for railways in which cartridges contained
in a gravity-operated magazine are successively brought under the control of
a train-operated escapement into position to be exploded, the combination with
a pivotally-mounted gravity-operated firing hammer and with means as described
whereby the force of the explosion is utilized for re-setting the hammer to the
operative or set position, of means whereby an audible signal is given in
the signal cabin consisting of a switch in circuit with an electric bell and operated
by means of a cam fixed on the axis about which the hammer rotates in its fall
substantially as and for the purpose specified.
"3
9. The herein described explosive signalling apparatus for railways substantially
as described and shewn in the drawings.
Dated thin th
C
1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.