IMPROVEMENTS IN THE MEANS AND APPARATUS FOR AUTOMATIC FOG SIGNALLING ON RAILWAYS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Owen Willmer White and William
Sinclair at the Office of the Commissioners of Patents on the 14th
November 1883.
OWEN WILLMER WHITE of St Pancras Iron Works, Engineer, and WILLIAM
SINCLAIR of Goldington Street, Patern maker, both of London in the County
of Middlesex-"IMPROVEMENTS IN THE MEANS AND APPARATUS FOR AUTOMATIC
FOG SIGNALLING ON RAILWAYS
This invention has for its object Improvements in the means and apparatus for
automatic Fog signalling on Railways and consists in an improved automatic
apparatus which will indicate to the driver or person in charge of a train, or other
moving vehicle, that the semaphore or other signal indicates danger; which
indications are repeated automatically without any manual alteration of the
apparatus, as often as a danger signal may be passed, the number of such
indications depending upon the number of charges placed in the apparatus.
In carrying our invention into practice we construct a small and compact
apparatus, the whole contained within a cast iron or other suitable covering.-
This apparatus is so arranged that in foggy weather connection can be established,
by a system of levers, with the rod of the semaphore or other signal usually
connected with the signal cabin and under control of the signalman, so that when
the signal indicates danger, or when the semaphore or light cannot be plainly
discerned, the apparatus is so set that a bar attached to the base will be brought in
contact with a properly fixed and suitable collapsing stud, hinged lever, inclined
plane, or otherwise, so that the mechanical arrangements hereafter described will
cause the explosion of a detonating mixture and thus draw the driver's or
responsible officials attention to the fact that the signal indicates danger; or instead
of a detonating mixture, we can use a gong, bell, or other suitable apparatus for
calling attention to the danger signal.-The apparatus can either be fixed upon the
locomotive or other moving vehicle or upon the signal post as may be most
convenient. In the former case the rod actuating the striker is carried down to a
point above or about the rail level. This bar is bent near its upper end to an angle,
and centred at that angle, so that when struck out of its normal vertical position
the angle arm at the top is raised to a vertical position. The top end of this upper
arm is fitted with a hinged crank, having a stud thereon, travelling in a slot and

page_text: suitably guided, which crank impinges against and actuates the striker, the lower
extremity of the vertical rod has a suitable foot or termination which when the
signal is at danger, strikes against the collapsing stud, hinged lever, inclined plane
or other suitable striking plate. In the employment of an inclined plane, it may
be advantageously depressed by the flanges of the wheels, and the said plane of
such length as not to be affected by any number of wheels, that may pass over it.
The aforesaid striking plate arrangement above or about rail level is connected with
the semaphore or signal rod, or wire, worked from the cabin, so that when the signal
is at "safety," it is out of the line of the bar fixed to the moving vehicle or
locomotive, but when the signal is at danger it is moved forward into the said line
and is struck by the foot of the bar attached to the engine and thus actuates the
striker and causes a detonation or other signal indicating danger, to the official in
charge. When the apparatus is fixed to the signal post, the arrangement differs in
that the rod fixed to the passing vehicle is stationary and by striking against the
striking arrangement actuates the rod of the apparatus hereinbefore described and
attached to the signal post. In order to prevent more than one detonation occurring
by any number of wheels, if necessary we fix a small catch upon a hinge or pivot
fitted in a metal box and held in position by a spiral spring. This catch passes
through an aperture in the lower part of the case and is arranged in such a position
that the steel catch engages in a hole, made for its reception in the shaft of the
striking piece. To the outer end is attached a rod or wire connected with the
working bar of the signal, controlled from the signal cabin and thus after a
detonation the striker is held up whilst the train or any number of wheels pass
over the apparatus; the catch is withdrawn by the altering of the signal to safety
and the striker falls into its normal position. The mechanism which we use consists
of an intermittent rotating disc having any convenient number of spaces around
its side or periphery, which spaces receive the detonating charges and the number of
these correspond with the number of teeth on a ratchet wheel. We impart motion
to the ratchet wheel by means of a pawl cranked to a lever, which lever is firmly
fixed at right angles to the striker just below the head thereof and thus at each
impulse of the striker the ratchet or disc receives a partial rotary motion of the
distance of one tooth. The distance of the travel of this disc is still further
regulated and determined by a second set of teeth, on the ratchet wheel, having
contrary angle of teeth, which at each step is locked by a pawl acting in unison
with the other mechanism, to which other pawl we fix a weighted sleeve to
determine its accurate action. We also affix to the striker an indicating needle,
working vertically with the striker so that the position of the striker can be at
once determined. We place the charges in the respective places by means of a small
door or fap with staple and padlock.-On the centre disc shaft we place a dial,
which dial is seen on the front of the Cover, with the number of detonators marked,
and which dial-being actuated by the disc shaft shows how many Detonators have
been discharged and how many remain.
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