An Improved Detonating Railway Signal.
Year: 1893

page_text: Date of Application, 11th Sept., 1893-Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
An Improved Detonating Railway Signal.
I, JOHN PATRICK O'DONNELL, of "Fingall," Hammelton Road, Bromley, in
the County of Kent, Civil Engineer, M. Am. Soc. C.E., M.I.M.E., 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:—
My invention consists in an improved form of operating detonators applicable
either in connection with the switches or signals on railways.
"
"
My apparatus is arranged that if desirable a detonator may be placed in position
for explosion when the signal is either in the "danger" attitude or in the "safety
attitude, and if it is desired that the explosion takes place only in the "danger
attitude of the signal then a dummy can be fixed or only one opening made in the
detonator carrier or disc.
My invention consists of a striking piece fixed adjacent to the rail, which is
operated by the tread of the wheel of a passing vehicle or locomotive.
Working with the striker and forming part of it, is a suitable spring. Underneath
the striker is the disc which is employed for carrying the detonators from the
magazine into position underneath the striker and on the top of the base plate. In
the disc are arranged two openings into which the detonators fall or are forced from
the magazine by the spring into position.
For the purposes of description the drawings illustrate two openings in the disc;
in the normal position one of these is arranged at the opening of the magazine for
the detonators to be pressed into position in the opening of the carrying disc, and
when the disc is revolved half a revolution the end in which the detonator is held is
moved into position under the striker; the other hole or opening in the carrying
disc is now in position to receive a second detonator from the magazine. The base
plate is arranged bevelled, and on each side between the striker and the magazine
are openings for the discharge of what remains of the exploded detonators to fall
clear of the machine. Attached to the machine is a circular magazine, in the centre
of which is a spindle and round the spindle is arranged a spring. From the spindle
a finger is provided with an end corresponding to the top of the detonator, which is
employed for pressing the detonators into position.
The means I employ for operating the machine consist in a rack and pinion
movement, the rack being attached to the signal wire in connection with any known
means for ensuring a certainty of movement every time.
For the purposes of
illustration I use a motion plate which ensures the desired movement of the rack
every time, irrespective of the expansion or contraction which takes place in the
signal wire. By this means I ensure that the carrying disc always moves exactly
into the same position for charging and for explosion.
In order that my invention may be better understood and more readily carried
into effect I will proceed to describe the drawings hereunto annexed. The same
letters refer to the same parts in the several figures of the drawings.
Figure 1 is an elevation of my apparatus, showing the relative positions of the
parts of my machine in contact with the rail.
Figure 2 is a plan of Figure 1.
Figure 3 is a section X-Y of Figure 1.
Figure 4 is a section V-W of Figure 1.
Figure 5 is a section T-U of the magazine Figure 1.
a is the upper part of the striker, b is a spiral spring working in a recess
surrounding the lower part of a, c is the lower part of the striker and is a separate
niece. d is a pin inserted to make the upper and lower parts of the striker operate

page_text: as one provided the spring is not compressed.
e is a bolt inserted in the side to
keep the pin d in position, f is a small hole provided when e is withdrawn for
driving the pin out, g is the rail, h, h¹ are bolts, for bolting my machine to the
web of the rail, is the cover or case in which all the moving parts operate, k, k¹ are
rollers provided for easing the movement of the carrier, operating in connection with
the pinion and holding the rack in position, is the disc, m is the pinion and n the
rack, o is the magazine, o' is the spindle round which the spring o' is coiled, o* is the
finger keyed to the spindle o¹ having a termination of corresponding to the top of
the detonators, o is a pin to which is attached the end of the coiled spring, o' is a
stud for holding the other end of the coiled spring, a² is a slot in the upper part of
the striker a, a is the space allowed on the inside of the lower part of the striker
in the event of the spring b being compressed when the space underneath the striker
is filled, either in case of the signal being operated when the train is moving or in
case of a worn tyre, or both. The bevels, are provided for raising the striker
after the explosion.
They come in contact with the under side of the striker and raise it and it
remains raised as long as the full portion of is underneath, but as soon as
the opening in the carrying disc with the detonator is in position underneath the
striker the bevels are then in operation and allow the striker to rest upon the
detonator.
The action of my invention is as follows:-
The detonator is in position for explosion. On the passage of a wheel over the
striker a the latter is forced down on the detonator until, under normal conditions,
the parts, come in contact with the full parts P,, on either side of the
bevelled part of the carrying disc.
Assuming the normal position of the signal to be "danger" (and the explosion
has taken place), when the signal lever in the cabin operating the apparatus is
worked over and the signal is put to the "safety" attitude to allow the passage of
a train, the disc is moved round through the pinion m by means of the rack (which
is operated by the signal wire) revolving the pinion and turning the disc half
round so that the opening in which the detonator has been exploded is moved
round into communication with the magazine. When the opening has arrived in
position the finger o³, through the spring, forces another detonator into the opening.
If the signal is now put to " danger," the reverse action takes place upon the
rack, the pinion is moved and in its turn returns the carrying disc / so that the
opening with the detonator is moved into position under the striker. If now a
movement of a train takes place over the striker in the "danger" position of the
Bignal the detonator is exploded.
66
If it is desired that the explosion shall take place only in the "danger" position
of the signal then there need only be one opening provided, or if two, the second
opening may be filled with a dummy operating that after the explosion in the
danger" position of the signal, when the signal is worked to the "safety" attitude
the dummy is under the striker. The dummy is arranged with a recess corresponding
with the projection on the under side of the striker and acts that when in position
under the striker the projection falls into the recess in the dummy the striker then
being below the level of the rail. The striker rises immediately the rack and
pinion are operated by replacing the signal to the "danger" attitude. In that
working the hole in the disc with the detonator is moved in position under the
striker.
Another reason for forming the recess in the dummy is that it may slide freely
under the part where the magazine charges the disc so that the detonators cannot
fall, the recess being smaller than the detonator.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
-
1. In a detonating railway signal, the combination of a striker in a suitable case

page_text: the latter bolted to the web of the rail, with a revolving disc for carrying the
detonators from the magazine into position under the striker, substantially as
described and as illustrated in the accompanying drawings.
2. In a detonating railway signal, the combination of a revolving disc provided
with one or more openings for moving the detonators from the magazine into position
under the striker, of a rack and pinion movement operating the said disc, and of an
operating lever with wire or rod attachment connected to the rack, all substantially
as described and as illustrated on the accompanying drawings.
3. In a detonating railway signal as hereinbefore described, the combination of a
circular magazine in which a finger or operating piece is fixed, a spring working in
connection therewith so that the detonators are moved into position as the hole in
the carrying disc is moved into the magazine, all substantially as described with
reference to the drawings annexed.
4. In a detonating railway signal, the combination with the striker a, of the
spring b acting as connecting the two parts a and c of the striker by means of the
pin, the whole operating that any deviation from the normal movement of the striker
is taken up by means of the spring, the lower part of the striker c always keeping
a required uniform movement, substantially as described and as illustrated in the
accompanying drawings.
Dated this 11th day of September 1893.
JOHN P. O'DONNELL