IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS
Year: 1882

page_text: $6
LETTERS PATENT to Thomas Whittingham of Stansley Wood Blithfield Park
Rugeley in the County of Stafford for an invention of IMPROVEMENTS
IN RAILWAY FOG SIGNAL APPARATUS
"
PROVISIONAL SPECIFICATION left by the said Thomas Whittingham at
the Office of the Commissioners of Patents on the 28th April 1882.
THOMAS WHITTINGHAM of Stansley Wood Blithfield Park Rugeley in the
County of Stafford. " IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS
"
The object of this invention is to enable signalmen in the ordinary signal boxes
of railways to place detonating fog signals on to the rails whenever it may be
requisite for them to do so and to take off such fog signals when it is no longer
necessary that they should remain on the line-and to effect these operations by
the working of the ordinary hand levers used for working the semaphore signals.
For this purpose I fix alongside of the rails near to each distant signal or
wherever fog signals may have to be used a box or frame in which is a bar which
can slide to and fro in guides parallel with the rails and I connect this bar to the
ordinary signal wire by which the semaphore signal is worked so that the bar has
to move to and fro with the wire.
Alongside of this bar is a second bar which can also move to and fro in guides
or friction rollers and which can be coupled to or uncoupled from the first bar by a
moveable catch. When the fog signal apparatus is not required to be in use the
signalman can (by means of a wire passing to his cabin from a weighted lever
connected with the catch) lift the catch so as to uncouple the bars one from the
other.
The signal man can then work the semaphore signal by the signal wire in the
ordinary manner whilst the fog signal apparatus will remain out of action.
When the fog signal apparatus is to be brought into action the signalman can by
the movement of a lever handle or wheel slack off the wire by which the catch is
held up and allow the catch to drop and lock the two bars together.

page_text: The second bar which only moves to and fro when locked to the first bar has
standing out from it a horizontal plate in which is a slot.
A pin on one arm of a bell crank lever enters this slot and the to and fro
movement of the plate gives a to and fro partial return to the lever. The central
or acting portion of the slot is at right angles to the rails whilst the ends of the
slot are parallel with them and may extend to any desired length. The lever
does not move when the pin upon it is in either one or other of the end portions of
the slot.
In this way the bar may have more or less movement given to it and yet the
movement given to the bell crank will not vary-this allows for slack and expansion
or contraction of the signal wire.
The other arm of the bell crank gives a to and fro motion to a horizontal slide
which works at right angles to the rail.
Above the forward end of the slide is a vertical hopper containing a pile of
detonators one above the other. Each detonator has a wire stem standing out
from it and the wire is so bent as to form a T head at the end of the stem.
Upon the inner sides of the hopper are vertical wires against which the edges of
the detonator bear, these form guides to keep the detonators with their T heads all
one over the other and yet allow the detonators to descend with but little friction.
In the forward end of the slide is a T shaped slot into which the Theaded stem
of the detonator can enter. When the slide is drawn back past the bottom of the
hopper the lowest detonator in the hopper drops down in front of the end of the
slide and its T head enters the T slot in it.
When the slide is moved forward it pushes the detonator forwards along a
horizontal surface which is level with the top of the rail on to which the detonator
is to be placed and moves the detonator onto the top of the rail.
If a train then pass over the rail the detonator would be exploded.
When the signal man again lowers the semaphore signal arin the slide is drawn
back. If no train has passed over the detonator, the slide merely draws the
detonator back with it and when the slide is again moved forward it will again
carry the detonator on to the top of the rail. If previously to the slide being
drawn back the detonator has been exploded the wire stem of the exploded
detonator together with any portions of the detonator case which may be still
adhering to it will drop down through a slot and on the completion of the backward
movement of the slide a fresh detonator will drop down in front of its end from the
hopper

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Whittingham in the Great Seal Patent Office on the
28th October 1882.
THOMAS WHITTINGHAM of Stansley Wood Blithfield Park Rugeley in the County
of Stafford "IMPROVEMENTS IN RAILWAY FOG SIGNAL APPARATUS
"
The object of this invention is to enable signalmen in the ordinary signal boxes
of railways to place detonating fog signals on to the rails whenever it may be
requisite for them to do so and to take off such fog signals when it is no longer
necessary that they should remain on the line and if desired to effect these
operations by the working of the ordinary hand levers used for working the
semaphore signals.
For this purpose I fix alongside of the rails near to each distant signal or
wherever fog signals may have to be used a box or frame in which is a bar which
can slide to and fro in guides parallel with the rails and I connect this bar to the
ordinary signal wire by which the semaphore signal is worked or it might be to a
separate wire so that the bar has to move to and fro with the wire.
From this bar I give motion to a slotted plate which effects the placing of the
fog signals on to or the taking them off from the rails as herein after described.
The slotted plate may either be carried by a bar parallel with the first bar and
which can be clutched to it whenever the fog signal apparatus is to be brought
into action by means of a catch operated by a second wire from the signal cabin,
or as I prefer the slotted plate may be fixed to the bar which is coupled to the
semaphore signal wire and the slot in the plate then be so formed that its acting
portion can be brought into action or not by a hinged stop plate which can by
means of the second wire be brought into a position either to leave open the
entrance to this acting portion of the slot or to close this entrance as desired or
the slotted plate might be worked by the second wire itself if the apparatus is to
be worked independently of the semaphore signal wire.
A pin on one arm of a bell crank lever is made to enter the slot in the slotted
plate and the slot is so formed that the to and fro movement of the plate shall
give a to and fro partial turn to the lever. The central or acting portion of the
slot is for this purpose made at right angles to the rails whilst the ends of the slot
are parallel with them and may extend to any desired length. The lever does not
move when the pin upon it is in either one or other of the end portions of the slot
but the lever is turned when the portion of the slot which is at right angles to the
rails is acting upon it.
In this way the bar may have more or less movement given to it and yet the
movement given to the bell crank will not vary this allows for slack and expansion
or contraction of the wire which moves it and so admits of the apparatus being
fixed at any point between signal box and semaphore signal or beyond the signal
if necessary.
The other arm of the bell crank gives a to and fro motion to a horizontal slide
which works at right angles to the rail.
Above the forward end of the slide is a vertical hopper containing a pile of
detonators one above the other. Each detonator has a wire or other stem standing
out from it and the wire is so bent as to form a T head at the end of the stem.
Upon the inner sides of the hopper are vertical projecting ribs or wires or bars
against which the edges of the detonators bear, these forin guides to keep the
detonators with their T heads all one over the other and yet allow the detonators
to descend with but little friction.

page_text: In the forward end of the slide is a T shaped slot into which the T headed stem
of a detonator can enter. When the slide is drawn back past the bottom of the
hopper the lowest detonator in the hopper drops down in front of the end of the
slide and its T head enters the T slot in it.
When the slide is moved forward it pushes the detonator forwards along a
horizontal surface which is level with the top of the rail on to which the detonator
is to be placed and moves the detonator on to the top of the rail.
If a train then passed over the rail the detonator would be exploded.
When the signal man again lowers the semaphore signal arm or draws back the
wire to which the slide is attached the slide is drawn back. If it is desired to
leave a detonator on the rail when the semaphore signal is lowered the fog signal
apparatus can be thrown out of action. If no train has psssed over the detonator,
the slide merely draws the detonator back with it and when the slide is again
move forward it will again carry the detonator on to the top of the rail. If
previously to the slide being drawn back the detonator has been exploded the
wire stem of the exploded detonator together with any portions of the detonator
case which may be still adhering to it will drop down through a slot and on the
completion of the backward movement of the slide a fresh detonator will drop
down in front of its end from the hopper.
If two or three such apparatus are used in connection with the same signal wire-
they may as herein after described be formed so that the signal man may at will
place either one two or three fog signals on to the line at any desired distances
apart from one another.
Figure 1 shews a plan view of apparatus arranged as above described with the
slotted plate attached to the semaphore signal wire-Figure 2 is a side elevation
of the bed plate or frame and of the sliding bars carried by it. Figure 3 is a
vertical cross section of the apparatus. Figure 4 is a plan view of the apparatus
with the upper fixed plate removed.
In these Figures A is a portion of one of the rails alongside of which the bed
plate B is secured. C is a bar which can move endwise to and fro and which at
its ends is attached to the semaphore signal wire. D is a bar which is attached
to a second wire and which can not only be moved end wise to and fro but which
can also move sidewise a distance towards or away from the line of rails.
It has two pins standing up from it which enter slots E E in the top fixed
plate the two ends of these slots are parallel with the bar but an intermediate
portion is inclined as shewn-thus when the bar is moved endwise it is also made
to move towards or away from the line of rails. In the bar D is a longitudinal
slot into which enters a pin which stands up from the stop plate F. The stop
plate can turn around a pin F¹ which stands up from the lower bar C as is better
seen at Figures 5 and 6 which shew plan views of a portion of the bar C and of
the stop plate carried by it-when the bar D is moved towards or away from the
line of rails the stop plate will be moved either into the position shewn at
Figure 5 or into that shewn at Figure 6. From these figures it will be seen that
at this part of the bar a slot Cx is formed in it. One portion of the slot is at
right angles to the rails-at the end of this portion of the slot which is nearest to
the line of rails the slot is extended both ways in a line parallel with the length of
the bar and at the opposite end it is similarly extended in one way only. A pin
G standing up from the end of one arm of a bell crank lever G enters this slot in
the bar C. When the stop plate is in the position shewn at Figure 5 and the bar
C is moved in the direction shewn by the arrow the pin G' standing up from the
bell crank will enter and move along the portion of the slot which is at right
angles to the line of rail and the bell crank will consequently be turned upon its
axis. If however the stop plate is turned into the position shewn on Figure the
pin G will not enter this portion of the slot but will remain at rest and the bell
crank lever will not be turned. The bell crank turns on a pin G2 which stands up
from the bed plate B-the other arm of the bell crank is coupled by a connecting
rod H to a slide I which can move to and fro at right angles to the line of rails

page_text: below the bottom of the vertical hopper J which contains the supply of fog signal
detonators.
Figures 7, 8 and 9 shew views on a larger scale of this slide and the hopper.
Figure 7 is a plan view in section taken through the upper part of the hopper.
Figure 8 is a plan view in section of part of the slide moved forward into position
to place a fog signal onto the rail A. Figure 9 is a cross section through this part
of the slide.
From Figure 7 it will be seen that in the interior of the hopper J there are
vertical wires J' for the edges of the detonators to bear against so that the
detonators may descend with but little friction. K is one of the detonators with a
Tshaped head K' at the end of its stem.-The forward end of the slide I has a
correspondingly shaped cavity for the head of the stem to enter.
When the slide is drawn back to its full extent the lowest detonator in the
hopper drops down in front of the slide and the head of the stem of the detonator
drops into the cavity in the front end of the slide. When the slide is moved
forwards towards the line of rails it passes through a casing L which extends up
to the rail the detonator is pushed forwards in front of it and placed above the
rail as shewn at Figure 8-L' is a slot in the bottom of the casing L for the stem
of any exploded detonator to drop through and so be got rid of when the slide is
drawn back. The hopper J is provided with a hinged door J2 at the back to
facilitate its being filled with detonators.
From the above description it will be seen that whenever the stop plate is
turned into the position shewn at Figure 5 a detonator will be placed on to the
rail whenever the semaphore signal arm is set at danger and will be taken off again
whenever the signal is lowered-and that if the stop plate is turned into the
position shewn by figure the semaphore signal may be worked by its wire
without any fog signal being placed onto the rail.
If it be desired to place either one two or three fog signals on to the line at
distances apart from one another according to the varying positions of the
semaphore signal arm-three apparatus arranged as above described may be placed
along the line at distances apart from one another and the portions of the slots E
in the top fixed plate which are parallel with the line of rails can be so made that
when the second wire is moved a distance the stop plate of No 1 apparatus shall
be turned into position to bring that apparatus into action and with a greater
movement of the wire the second apparatus shall be brought into action and with
a still further movement of the wire the third apparatus shall be brought into
action.
Figure 10 shews a plan view of the apparatus arranged to be worked
independently by a wire separate from the semaphore signal wire.
In this figure A is the rail C is the slotted bar to which the wire is connected.
G is the bell crank-and J the hopper containing the supply of fog signal
detonators.
It will be seen that when the wire is drawn in the direction shewn by the
arrow the bell crank of No 1 apparatus will be at once turned and a detonator
placed by it onto the rail. Meanwhile the bell cranks of apparatus Nos 2 and 3
will have remained at rest.-A further movement of the wire will turn the bell
crank of No 2 apparatus and cause it to put a fog signal on to the line and a still
further movement will cause apparatus No 3 to put a fog signal on to the line.
Similarly with a backward movement of the wire No 3 detonator would be taken
off first then No 2 and then No 1 so that the signal man by moving the wire by a
hand lever or other mechanism in his cabin can place either one two or three fog
signals on to the line whenever he requires to do so.
An indicator may be placed in the signal cabin to indicate to the signal man
whether all of the three fog signal apparatus are out of action or whether one two
or three of the fog signal apparatus have been brought into action.
The construction of the fog signal detonators is shewn at Figure 7.
K' is the wire stem bent as shewn to form it with a T head the other end of the

page_text: stem projects a distance into the interior of the outer metallic casing of the
detonator and the metal of the casing is closed down on to it so as to hold it-the
inner iron cap containing the explosive is cut away just opposite to the end of
the wire stem so as to weaken it at this point in order that the explosion may
be directed mainly in the direction of the stem and so detach it from the casing.
Having thus described the nature of my Invention and the manner of performing
the same I would have it understood that I claim: —
First. The combination of mechanism for placing fog signals on to a line of
railway whenever required substantially as herein before described with reference
to Figures 1 to 9 of the Drawings annexed.
Second. The combination of mechanism for placing fog signals on to a line of
railway whenever required substantially as herein before described with reference
to Figure 10.
Third. The combination of the slot Cx, formed as described in the bar C with
the bell crank lever G connecting rod H slide L and hopper J all acting together
substantially as described.
Fourth. Lining the hopper J with vertical wires for the edges of the fog signal
detonators to rest against as herein before described.
Fifth. Forming a slot through the bottom of the casing through which the
slide I works substantially as and for the purpose described.
Sixth. The construction of the detonators with wire stems substantially in the
manner described.
In witness whereof I the said Thomas Whittingham have hereunto set iny
hand and seal this twenty seventh day of October in the year of our Lord
One thousand eight hundred and eighty two.