Improvements in Railway Fog Signalling Apparatus.
Year: 1898

page_text: Date of Application, 17th May, 1898-Accepted, 18th June, 1898
COMPLETE SPECIFICATION.
Improvements in Railway Fog Signalling Apparatus.
We, THOMAS WILLIAM MILLER, of No. 12, Temple Court, King Street, Sydney, in
the Colony of New South Wales, Engineer, and PERCY BRERETON COLQUHOUN, of 114,
Pitt Street, Sydney, in the Colony of New South Wales, Solicitor, 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 improvements in railway fog signalling apparatus of the
kind for which former Letters Patent were granted to us dated 28th September 1896,
No. 21462, and consists essentially of an improvement in the mechanisin employed to
raise the detonators from the underground magazine, and also an improved shield to
protect the open end of the apparatus and means to operate the same. The apparatus
itself is operated in a similar manner to that described in the Specification of Letters
Patent before mentioned.
But in order that the improvements may be more fully understood reference will
now be made to the accompanying sheet of drawings consisting of 4 sheets and in
which:-
Figure 1 is a plan of this improved railway fog signalling apparatus with the cover
removed.
Figure 2 is a fragmentary detail shewing connection to bell crank lever.
Figure 3 is a fragmentary side elevation with shield thrown forward shewing the
apparatus in its normal position.
Figure 4 is a side elevation shewing the shield thrown back, and the detonator on
the rail.
Figure 5 is a vertical central sectional elevation of Figure 4.
Figure 6 is a vertical cross section on line 1-1-Figure 1-looking from the rail
end.
Figure 7 is a vertical cross section on line 2-2 Figure 1, looking from the rail
end.
Figure 8 is a vertical cross section on line 3, 3, Figure 5 looking from the rear, and
with the lower pawl stop removed.
In all figures similar letters are used to denote similar parts.
A is the magazine which may be constructed of any depth according to the number
of detonators required to be stored; B is the carrier for supporting the detonators,
this carrier is provided with the extended side pieces C to which are attached the
lifting cords or chains D (one on either side.) These lifting cords or chains pass
over pulleys E, E, carried on the pins E', and wind round the drums F, F, carried on
the spindle G. H is the detonator secured to the mount I. J is the sliding bar or
piston connected to one arm of the bell crank K, by the rod L, to the other arm of
the bell crank is attached a wire M, leading one way to the operating lever or other
mechanism in the signal cabin, the other way over the pulley end is secured to the
counter weight 0. To the sliding bar or piston J, is attached (one on either side)
the rods P, P, used to operate another sliding bar or piston Q, to which they
are connected by the pieces P¹. This bar or piston consists of a piece cut out
of the centre of the bed R of the detonator passage or channel A2, leaving the two
strips R to support the detonator carriers as they travel forward, the slide Q, only
877

page_text: taking the weight of the detonator carrier when in its forward position as shewn in
Figure 5, the top of the slide Q, is slightly lower than the top of the strips R'. The
rods P, P, are also used to operate the shield S, the latter being connected to the
levers T, T, (one on each side) the upper ends of which are slotted U. These levers
are pivotted at V, and the lower ends W, are tapered. On each of the rods P, P, are
provided two blocks or tapered pieces X, X, the outer blocks forming the ends of the
rods. Y is a block placed on top of the shield S, having two projecting pins one on
each side Z, these pins projecting through the slots U, in the levers T, so that. when
the rods P, P, are drawn, the shield S, is forced forward to the front wall of
the apparatus, as shewn in Figure 3, and when the rods P, P, are forced forward the
hindermost blocks X, strike the tapered end W, of the lever T, and withdraw the
shield into the position shewn in Figure 4. In the side walls of the forward end of
the apparatus is provided an opening (one on each side) a, to permit of the pieces P¹,
passing to and fro, the latter as before mentioned operating the second sliding bar or
piston Q. The shield S is provided with a block or stop 6 to engage the heel of the
detonator carrier I, so as to prevent the detonator being forced too far (see Figure 5).
c is the covering plate turned upwards c¹, over the detonator magazine A, forming
the front and back of charging box, the sides are formed by planting on the plates c²,
inside the latter is formed a guide way for the rods P, P; the charging box is
provided with the cover d, which may be locked in any suitable manner. e is a
storage box or receptacle provided at the rail end of the apparatus to receive the
unexploded detonators as they are withdrawn from the rail, and is provided with
the opening or door f.
On the spindle G, and between the drums F, F, is mounted the pawl wheel g, the
drums and pawl wheel being secured together. This pawl wheel consists of a grooved
pulley having the pins, secured therein. The under side of the sliding bar J, is
provided with two blocks i, j, to operate the sliding pawl stop carrier, this latter
having an upward projection l, and placed between the blocks i, j, and sliding on
the bed m. An opening is left in the rear of the apparatus so that when the slide P,
is drawn out to its full extent the sliding pawl stop carrier may be withdrawn.
On the under side of this pawl stop carrier k, is placed the bracket n, to
which the pawl stop p, is pivotted at q, the forward end of this pawl stop engages
the pins h, in the pawl wheel g, and the rear end projects through the back of the
apparatus, as shewn in Figures 4, and 5. At the rear and near the bottom of the
apparatus is provided a block 7, to which is pivotted at t, the lever u, the inner end v
of which is curved to the same radius as the pawl wheel g, acting as a friction
brake thereon when required. A second pawl stop w, is secured to the top of this
friction brake as shewn in Figures 4, and 5, the upper end of this pawl stop also
engages the pins h, in the pawl wheel g.
To operate the apparatus and place a detonator on the rails x, the signalman will
actuate the mechanism in the signal cabin and release the connecting wire M, which
will allow the weight 0, to fall, this will cause through the intervention of the bell
crank lever K, the bar or piston J to enter the detonator passage. As this is taking
place the shield S is being withdrawn by the rear blocks X, X, striking the lever T.
The second slide Q, is also being operated upon and forced forward, to assume the
position shewn in Figures 1, and 5. The detonator and carrier are also being forced
forward by the sliding bar or piston J, and when the latter has travelled its full
limit the apparatus will assume the position shewn in Figure 5. The sliding bar or
piston J now covers the detonator magazine A, and is prevented from entering the
detonator passage too far by the stop P2, secured to the under side of the sliding
bar J as shewn in Figure 5, and the second slide or piston Q, covers the
opening A¹, in the bed of the detonator channel, and the pawl stop w retains the
pawl wheel g, keeping the uppermost detonator in the magazine immediately beneath
the forward end of the sliding bar or piston J. To remove the detonator from the
rail the signal man actuates the mechanism in the signal cabin in the reverse way.
This draws up the weight 0, and through the intervention of the bell crank K,
withdraws the sliding bar or piston J, at the same time withdrawing the rods P, P.

page_text: When the block j, on the under side of the sliding bar or piston J, strikes the
block 1, on the pawl stop carrier k, it forces the latter backwards and causes the
pawl stop p, to drag the pawl wheel g, around a given distance. As this takes place
the pawl stop w, is forced backwards by the travelling pins h, and when the next pin
has passed the hook of the pawl stop w, it falls forward again and engages that pin
and retains it until the wheel is operated again. The travel of the pawl wheel g, will
have been sufficient to wind the lifting cord or chain D on the drums F, F, and raise
another detonator into the correct position to be forced along the channel A². The
rods P, P, travelling with the sliding bar J, will cause the second sliding bar or
piston Q, to be withdrawn, leaving the opening A¹, in the bed of the detonator
channel uncovered, at the same time the shield S would be forced forward into the
position shewn in Figure 3. The detonator and carrier will then fall by its own.
weight through the opening A', into the storage box e. The distance of travel of the
block j, on the under side of the sliding bar or piston J, before it strikes the block 1,
on the pawl stop carrier k, is sufficient to allow the sliding bar J to be withdrawn so
much that the inner end will be clear of the rising detonator.
When the magazine has become empty, it would be recharged from the top, after
removing the cover d. To lower the carrier B it is necessary to force downwards the
outer or projecting end of the pawl stop p, and at the same time the outer or
projecting end of the lever u this will cause the pawl stops p, w, to release the pawl
wheel g, and at the same time bring the friction brake v, into play against the
periphery of the pawl wheel g. The latter being now free to revolve the carrier B in
the magazine A, can be allowed to fall as required. In charging the magazine it is
necessary for the successful operation of the apparatus that it be quite fully charged,
and if there be not sufficient detonators to do this, the carrier B, must be lowered
only so much that when the supply of detonators is placed in the magazine the
uppermost one will be in the correct position for firing, otherwise it would be necessary
to operate the sliding bar or piston J, backwards and forwards until such time
as the carrier B, had been raised sufficiently to bring the uppermost detonator into
position.
A modification may be made if it is thought desirable to provide some counter
balance to the weight of the detonators in the magazine, by securing the drums F, F,
and the pawl wheel g, to the spindle G, and on one side of the apparatus where the
spindle G projects to provide a strong coil spring one end (the inner) of which would
be secured to the spindle G, the other or outer end fastened to the side of the
apparatus and so arranged that when the carrier B is lowered and the lifting cords or
chains unwound off the drums, the coil spring will be wound and thus provide a
counter balance to the weight of the detonators, and as the carrier B, would be raised,
and the lifting cords or chains wound on the drums, the coil spring would unwind and
thus compensate the weight proportionately.
An insulated bar B1 is secured to the under side of the carrier B and projects
slightly beyond the extended sides C, so that when the carrier B rises in the
magazine to any desired point it will make contact with an electrical connection on
each side and cause the current to travel to the signal cabin in which an electric bell
and indicator is placed, this is to warn the signalman that the magazine requires
re-charging. It will be obvious that many modifications may be made in the method
of making the electrical contact.
In the construction of this apparatus it is preferable to use metal throughout,
constructing the sliding bars of steel. The detonators used are the ordinary
commercial article, enclosed in a tin case, more particularly shewn in the Letters
Patent before referred to, and as the apparatus would be mostly below the level of
the rail it is preferable a pit be made in which to place it.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1st. In mechanical railway fog signalling apparatus the combination with an

page_text: underground magazine, of lifting cords or chains, a pawl wheel having a winding
drum on either side, and supported on a spindle placed at the rear of the said
underground magazine, the pawl wheel being operated upon in such a manner
as to raise the detonators from the underground magazine into the required
position substantially as herein described, explained and illustrated in the
drawings.
2nd. In mechanical railway fog signalling apparatus the combination with an
underground magazine of a carrier and lifting cords or chains attached thereto, a pawl
wheel and winding drums, a sliding pawl stop carrier, having on the under side
thereof, a pawl stop and operated upon by a sliding bar or piston used to force the
detonators on to the rail, a lower check pawl stop to engage the pins or the said pawl
wheel, and a friction brake, substantially as herein described, explained, and illustrated,
in the drawings.
3rd. In mechanical railway fog signalling apparatus the combination with an
underground magazine, of lifting cords or chains, a pawl wheel and winding drums
actuated by pawl mechanism, a sliding bar or piston to force the detonators on to
the rail, two side bars or rods attached at one end to a sliding bar or piston and at
or near the other end provided with blocks or projections to engage a vertical lever,
the latter operating a shield or cover for the rail or open end of the apparatus,
substantially as herein described, explained and illustrated and for the purposes set
forth.
4th. In mechanical railway fog signalling apparatus the combination with an
underground magazine, of a carrier placed therein, of lifting cords attached thereto,
and mechanism for operating saine, of a shield formed in the covering plate, and
adapted to be moved forward and backwards as required to protect the open
or rail end of the apparatus, and having a block or stop attached to the outer
under end of the said shield to engage the heel of a detonator mount or
carrier, substantially as herein described, explained, and illustrated in the
drawings.
5th. The combination and arrangement of the various parts herein described,
explained, and illustrated, altogether forming the improvements in railway fog
signalling apparatus, substantially and for the purposes set forth.
Dated this 17th day of May 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.