IM- PROVEMENTS IN MACHINERY OR APPARATUS FOR ACTUATING FOG OR DETONATING SIGNALS ON RAILWAYS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by James Randall and Charles Adams
at the Office of the Commissioners of Patents, with their Petition, on the
30th March 1867.
We, JAMES RANDALL and CHARLES ADAMS, both of Kilburn, in the County
of Middlesex, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN MACHINERY OR APPARATUS FOR ACTUATING FOG OR DETONATING
SIGNALS ON RAILWAYS," to be as follows:-
This Invention relates to certain improvements in machinery or apparatus
for the purpose of actuating detonating or fog signals on railways, the object
being to place the signal at the requisite distance from the station or points-
man's box, and to withdraw or discharge the same by the passage or transit of
a train without the necessity of placing the signals on the rails by hand.
We propose according to our Invention to employ a lever set in a guide or
slotted arc, and having its fulcrum below or at the lowest part of the
foundation of the guide, the lever being provided with a sliding hand lever
which falls into notches on the guide after the ordinary manner of working
signal levers; to the lower portion of the lever a horizontal connecting rod is
joined, which is pivoted to a cross bar working or oscillating on a vertical
stem fixed on a bed plate on the ground near the signal box or station; to
this cross bar at its opposite extremity a long rod or series of rods is joined ;
these rods extend to the requisite distance down the line at which it may
desired to explode the signal by the passing train, and are supported by
standards or bearings in the ordinary manner. To this rod or series of rods a
similar cross bar or rocking lever is attached near the position at which the
be

page_text: signal is to be given, the apparatus for effecting which is as follows:-On a
long foundation plate supported by side plates we place and fix a vertical tube
having a moveable top or cap; the tube let in a socket formed in a block
attached to the foundation plate; the block has a space cut out between the
plate and tube for the purpose of receiving a horizontal sliding bar which
passes through it and along the plate, and is worked by means of the cross
bar attached to the long rod or series of rods; it therefore receives a
reciprocating motion from the distant signal lever first mentioned. Now the
extremity of the slide bar is formed with a pronged or forked termination
with a semicircular internal space, it is held in position by two slotted guides
bolted to the foundation plate, and is connected to a second sliding plate
underneath the foundation plate by means of a pin or other means, so that
the two move together, and when the under plate is thrust forwards it rests
on a block or support within the sides of the foundation plate, which has a
circular perforation made therein above the block, the block itself being also
perforated or provided with a shallow well or receptacle. The tube is to be
supplied with any number of detonating or fog signals, one above the other
like a pile of coin, and it will therefore follow that if the forked slide be
drawn back by the signal lever till it comes under the tube one of the signals
(that is to say, the lowermost one) will drop on to the foundation plate within
the fork of the slide, then the signal lever being reversed the slide will go
forward, carrying the detonator to the circular perforation on the plate, but
when it reaches that position it drops on to the under slide, and is there left
for discharge by a passing train, and when discharged, the slide being again
removed by the signal lever, it will fall into the well or recess formed in the
block, and the operation may be repeated for the next train.
It now remains to describe the method by which the detonator is exploded.
It being of course understood that the above apparatus is placed alongside
the line of rails, we set a shaft in bearings in a position transversely to the
line extending under and within the outer rail, under the slide and under the
moving series of rods within the rail, the shaft carries a curved arm which is
keyed to it, and extends to a level a little above that of the flanges of the
wheels of the train; at or near the other end of the shaft a tooth or catch is
keyed, which enters a notch cut in the under side of a horizontal bar set in
grooved bearings on standards fixed to a bed plate or otherwise. Now in
addition to the distant signal lever operating the rod or series of rods which
actuate the first portion of the apparatus the cross bar which it works pulls a
chain or wire attached to this horizontal bar, and draws it into position for
the catch to enter the notch, the catch being kept up by means of a counter-

page_text: weight on the opposite side of the transverse shaft, the other end of the
horizontal bar is again connected to a second chain or wire, which is joined to
a vertical arm or crank keyed to a short shaft set also in bearings transversely
to the line; this shaft also supports a hammer, the handle being fixed to the
shaft in such position that when the bar is pulled towards the signal lever the
hammer will be raised to a certain distance. Now the head of this hammer
falls when released on to the detonator, its position being arranged accordingly;
when the train or engine passes the curved arm within the rails the flanges of
wheels bear it down and release the catch from the bar, the weight and
leverage of the hammer are then brought into play and the detonator is
exploded.
Should a fog signal be brought over the perforation and an approaching
train should not require to be signalled it is only necessary for the signalman
to withdraw the slide and the signal drops into the well. The train passes
along, but although the curved arm is forced down by the flanges and the
catch borne down the bar is held in position by the tightness of the chain
from tightness of the chain from the signal level, the chain of course only
being slack when the signal lever has pushed forward the detonator ready for
explosion. The rods from the signal lever may be of any length, and may
work duplicate sets of apparatus if required, the principle being the same.