IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS
Year: 1876

page_text: LETTERS PATENT to John Smith, of No. 8, Hardees Street, Camberwell, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN RAILWAY FOG
SIGNAL APPARATUS."
Sealed the 11th May 1877, and dated the 14th November 1876.
PROVISIONAL SPECIFICATION left by the said John Smith at the Office of
the Commissioners of Patents on the 14th November 1876.
JOHN SMITH, of No. 8, Hardees Street, Camberwell, in the County of Surrey.
"IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS."
The object of this Invention is to provide a simple and efficient apparatus by
which fog signals may in foggy weather or otherwise be audibly heard by engine
drivers and guards in charge of trains, as it is at all times in working order when
the signal is at danger.
When the signal is at danger, driver arriving at a distant signal will be attracted
by the apparatus commencing to ring, and guards' attention will be drawn to it as
each wheel passing through the apparatus will strike the gong or bell. No difference
in working should a train have to back through the apparatus. When distant are
at danger, by a spring cam aud leverage connected with the signal I can indicate to
driver that the line is not clear only to the stop signal.
The above is worked on the following principle:-I place a spring cam on between
the rails on the sleepers, and by rod connected with cam, and that is connected to
crank, and from that to bell leaver, and bell lever is worked to a stop that can only
strike when the signal is at danger. The above bell or gong is placed on signal
post on the weight carrying lever, with an extra lever added to keep it in position ;
that takes the bell or gong away when the signals are taken off the bell or gong,
substituting a portion of weight required, or a fixed gong may be used.
By employing apparatus such as is described above, simple in construction, will
require no manual labor or expensive explosive, indicating correctly the position of
signal on a train approaching.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said John Smith in the Great Seal Patent Office on the 11th May 1877.
JOHN SMITH, of No. 8, Hardees Street, Camberwell, in the County of Surrey.
* IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS."
Hitherto it has been the practice to employ detonating signals to give warning on
railways in foggy weather of the approach of a train. Such detonating signals are
in themselves costly, whilst the necessary labour and attendance in employing them
adds considerably to the expense of this systein.
Another great disadvantage of this system is that any negligence on the part of
the attendants is frequently attended with fatal results. Now the object of my
Invention is to thoroughly obviate these various disadvantages, and so considerably
to reduce the cost that on a monthly average the cost is reduced to an infinitesimal
degree.
And in order that my said Invention may be better understood, and more readily
carried into effect, I will now proceed to describe the same, reference being had to
the accompanying Drawings, whercon similar letters of reference indicate corres-
ponding parts.
Figure 1 shews an elevation of my improved automatic apparatus applied to a
signal post; Figure 2 is a plan of the self-acting mechanism for giving audible
signals; and Figure 3 is one form of arrangement suitable for affixing the apparatus
to a wall or at the entrance of a tunnel or otherwise, where an audible signal
serves the important purpose of indicating the approach and also the distance of a
train.
Between the rails A. I fit a long spring lever B, which is bolted to a suitable
sleeper beneath the rails. The free end of this spring lever terminates in a laterally
projecting head piece C, which touches the contiguous rail A. At this part the
lever is secured to a flat bar or lever D, which is free to move in the transverse
direction of the rails, the outer end of such lever D extending to a convenient
distance outside the rail, while its free extremity is connected to a bell-crank
lever E. The free end of this bell-crank lever has fastened to it a rod, wire, or
chain F or its mechanical equivalent, which actuates the clapper G that strikes the
gong or bell H.
The arrangement or system of fitting the bell and the motive or actuating parts
connected therewith must obviously depend upon the position of the signal post,
and of the mechanical details of the permanent way of that part of the line where
the apparatus is affixed.
Figure 1 shews one method of arranging my improved apparatus. His the bell
secured by a central bolt and nut to a link I, which connects the two levers K and L
so as to cause them to work is unison. The lower lever L works on a pivot pro-
jecting from the signal post M. The upper lever is centred in like manner, and
rests (when in position shewn in the Drawing) upon the stop N, in which position
the bell H is struck by the clapper G.
To prevent any injurious lateral motion or loosening of the bell a stop O is fixed
to the signal post, which extends outwards to the link, and prevents any lateral
action. The upper lever K is connected by the vertical rod P to the danger signal Q.
During foggy weather the apparatus would be maintained in the position shewn in
the Drawings, and upon the train approaching the lever B each wheel as it passes
causes the lever to move aside, and thus actuates the crank E and the signal rod or
wire F of the clapper G. By this means, as each wheel passes the lever B, a powerful
blow is struck on the bell H.
When the line is clear the signal gong is kept off until the train has gone by by
the signalman actuating the wire or cord R.
Figure 3 shews one method of arranging my improved signal apparatus when
affixed to a wall or at the entrance of a tunnel or otherwise. H is the bell secured
to a bell-crank lever S, which is centred on a pivot behind the bell, and when

page_text: the audible signal is not required it is raised, as before described, by the wire or
chain T.
In this way a complete and efficient system of automatic signalling is obtained,
simple in its arrangement, economical in cost, and totally dispensing with manual
attendance and the use of detonating signals.
Having now particularly described and ascertained the nature of my said Inven-
tion, and the manner of carrying the same into effect, I would have it understood
that I do not confine myself to the precise details herein-before set forth and
described, as the same may be varied without departing from the principle of my
Invention, but what I claim is,―
Firstly. The employment of a spring lever placed beside the rail or otherwise
suitably arranged, whereby an audible signal is given to indicate the approach and
position of a train.
Secondly. The connecting such spring lever by the apparatus herein-before described
or its mechanical equivalent or equivalents, to a bell, whereby audible signals are
produced in the manner and for the purposes before described.
Thirdly. The mechanically raising such bell when not required for use by the
means herein-before described, or any mechanical equivalent or equivalents therefor.
In witness whereof, I, the said John Smith, have hereunto set my hand and
seal, this Eleventh day of May, in the year of our Lord One thousand
eight hundred and seventy-seven.