Improvements in Fog Signalling Mechanism for Railways.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Fog Signalling Mechanism for Railways.
I, ALFRED FREDRICK ANDREWS, of 20, New Road, Sawstone, in the County
of Cambridge, Railway Signalman, do hereby declare the nature of this inven
tion to be as follows:-
This invention relates to fog signalling for use on railways and its object is
to provide an automatic system of fog signalling whereby the present dangerous
and costly method of placing the signal in place by hand is avoided.
The invention consists generally in placing mechanism alongside the rails
so constructed that detonators may be fired by the passing train and exploded
detonators ejected while fresh ones are placed in position. Further this auto-
matic mechanism is so designed that it can be put into or out of operation by
the signalman from his cabin, and all in a manner hereinafter more particularly
described.
In carrying this invention into effect the construction and operation is as
follows: Immediately alongside the rail and preferably parallel with it a
pivotted lever is placed. This pivotted lever is attached at its free end to a
second lever fixed upon a short cross spindle. When the train passes the pivotted
lever it operates the second lever by depressing it, balance weights or suitable
springs fastened on an extension being employed to return it to the first position.
The second lever operates through link work upon a pawl and for one down-
ward movement causes the said pawl to rotate a horizontal disc one tooth for-
ward, corresponding pawl teeth being formed upon the said disc for this purpose.
Forming a portion of the disc which is rotated by the pawl is a circular exten-
sion with perforations or recesses to receive detonators, and one movement of
the pawl rotates the disc a sufficient distance to bring one perforation or recess
underneath a striker and simultaneously bring other perforations underneath
feeding tubes, and the exploded detonator underneath an automatic ejector.
The striker consists of a short punch or stop attached in any suitable manner
to the second lever and underneath it. When the train passes the punch moves
downwards and strikes the detonator contained in the recess giving the required
signal and when the weights or springs return the second lever to its unde-
pressed condition the pawl moves the disc forward and this brings a fresh deto-
nator underneath the punch and simultaneously brings the exploded detonator
over a recess.
This exploded detonator may be of such a size relatively to the perforation
within which it lies that it falls through into the recess, but it is preferred to
make the ejection positive and in the following manner:-An ejector punch
or stop slightly smaller in diameter than the perforation, is attached directly
to the second lever or by suitable link work in such a manner that simultane-
ously with the firing of a detonator upon the downward movement of the second
lever an ejector punch passes through the perforation so as to automatically
eject the exploded generator.

page_text: The feeding mechanism is arranged as follows:-One or more vertical tubes
are placed immediately adjacent to the rotating disc and in such a position over-
head that when filled with detonators these drop into the empty recesses or
perforations after having passed the ejector. The bottom of these tubes is
immediately over the recesses or perforations and in their circular path so that
the total weight of the detonators presses down the bottommost into the perfo-
ration. It is evident that positive mechanism to feed down the detonators into
the perforations could be used instead of the weight, that is to say a piston
could be fitted to the tubes having a movement corresponding to the thickness of
one detonator with each movement forward of the disc.
The striker or punch which explodes the detonator can be thrown out of
action by the fixed signal working in connection therewith, the signal at danger
locking the striker to the mechanism moved by the swing lever at the side of
the rail and when standing at line clear unlocks the striker so that the passing
of a train even though it depresses the lever does not move the striker and this
is effected by placing mechanism to lock the punch to the moving lever or not
as desired according to the circumstances of the case and this locking can be
effected by a wire from the signal cabin. This throwing out of gear could also
be effected by pulling the pawl out of action which moves the disc forward one
tooth the punch will then strike an exploded detonator only.
To prevent the disc with the perforations rotating backwards pawl teeth may
be formed on its outer periphery gearing with the safety pawl placed in a reverse
direction to the pawl used for moving the disc then the disc can only move one way.
T
1
.
100
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
improvements in Fog Signalling Mechanism for Railways,
I, ALFRED FREDRICK ANDREWS, of 20, New Road, Sawstone, Cambridge,
Railway Signalman, 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: -
This invention relates to fog signalling apparatus for use upon railways and
its object is to ensure automatic and certain operation of the apparatus and is
designed to avoid the present dangerous and costly method of placing the
detonating signal in position on the rails by hand.
According to the invention the detonating signals are fired by the passing
train and after explosion are ejected and fresh ones are placed in position. The
apparatus is so designed that it can be put into or out of operation by the signal-
man from his cabin and is constructed as hereinafter more particularly described.
The invention is illustrated in the accompanying drawing in which,
Figures 1, 2 and 3 are respectively side elevation, plan and end elevation of a
fog signalling apparatus constructed according to the invention.
Figures 4 and 5 are respectively side elevation and plan of a similar apparatus
of modified construction.
Figure 6 is an elevation of an operating lever attachment connected with the
rail.
In carrying the invention into effect an operating lever a is pivotted at b
immediately alongside the rail c. The free end of the operating lever a is loosely

page_text: connected to a shorter transverse lever d pivotted on a short cross spindle e
within a bracket g. The lever d is provided with a counterweight f which main-
tains the end of the lever a normally above or near the level of the rail so as to
be depressed on the passage of a train or engine. The said lever d is formed
with a vertical slot through which passes the upper extremity of a striker o.
Lugs p are provided as extensions of the sides of the slot and these lugs pl
carry between them a pawl lever 2 which is adapted to engage with the striker o
whenever the lever d is depressed. The striker o is supported preferably at its
lower extremity by a pin or trunnions held within the forked extremity of a
lever which lever is provided with a counterweight fl to return the striker to
its normal upper position after it has been depressed by the lever acting
through the pawl lever p. The lever his pivotted upon a cross shaft i whose
oscillating motion upon the depression of the striker is transmitted through a
lever arm j, link k and lever to a pawl m pivotted upon the lower extremity
of the lever and effects the rotation of a perforated ratchet disc n with which
the pawl m engages. The return of the striker o effects the movement of the
ratchet disc n such a distance as to bring the recesses q within it, successively
beneath the striker o. The recesses are each intended to carry a detonator and
when the lever a is depressed by a passing train the striker is engaged by the
pawl lever p and forced downwards by the lever d so as to strike and explode
the detonator in the recesses underneath it. After the train has passed the
counterweights f f return the levers a and h with the striker o to the normal
position and at the same time the disc n is moved forward and a fresh detonator
brought under the striker ready for the next depression of the striker.
The detonators are preferably supplied to the ratchet disc n from one or more
vertical tubes r containing a number of detonators and arranged adjacent to the
face of the disc immediately over the circular series of recesses so that as these
latter pass underneath the tubes the detonators drop into place one by one.
The detonators after being fired are allowed to drop out of the disc n through
an openings in the base plate of the apparatus as shown in Figures 1, 2 and 3
or they may be positively discharged by forming the end of the striker with an
additional plunger so that as the striker fires a detonator it also forces out the
detonator previously fired. This arrangement is shown as applied in the modi-
fication illustrated in Figures 4 and 5 wherein also the recesses are provided
in duplicate for ensuring certainty of detonation; the striker being arranged
with duplicate firing plungers tt and discharging plungers u u.
A pawl is mounted adjacent to the ratchet disc for the purpose of pre-
venting too great a movement of the ratchet disc and for the purpose of deter-
mining positively the extent of movement necessary to bring the next recess
containing a detonator beneath the striker. The pawl for this purpose engages
with peripheral ratchet teeth and is held up to engage therewith by means
of a weighted lever 10. Its disengagement is effected on the backward move-
ment of the pawl m by contact of the extremity of the lever with the pro-
jection upon the pawl for the purpose of the forward movement of the
ratchet disc.
The striker o can be thrown out of action from the signal cabin by lifting
the free end of the pawl lever p so that its other end is disengaged from the
striker and in this event the depression of the operating lever d has no effect
in operating the striker.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. A fog signalling apparatus capable of automatic operation on the passage
of a train consisting of a striker which on depression strikes a detonator and on

page_text: its return movement effects the rotation of a disc situated beneath the striker
carrying a series of detonators substantially as described.
2. fog signalling apparatus capable of automatic operation on the passage
of a train consisting of a striker which on depression strikes a detonator and
on its return movement effects the rotation of a disc situated beneath the striker
carrying a series of detonators, the upper extremity of the striker being con-
nected to a lever transversely disposed thereto and by means of which the striker
is depressed substantially as hereinbefore described.
3. In fog signals such as hereinbefore described means for operating the
striker by means of a pawl which is capable of being brought into engagement
or disengagement on operation from the cabin substantially as described.
4. A fog signalling apparatus operated upon the passage of a train consisting
of an operating lever mounted adjacent to the rail, a transverse lever connected
therewith and a further lever mounted beneath the latter and carrying a striker
whose upper extremity is connected to the upper transverse lever and is capable
of disconnection, and mechanism for rotating a ratchet plate mounted beneath
the striker and having a circular series of recesses within which detonators are
fed substantially as hereinbefore described.
5. A fog signalling apparatus constructed and operating substantially as here-
inbefore described and as illustrated in Figures 1 and 3 of the accompanying
drawings.
6. A fog signalling apparatus constructed and operating substantially as here-
in before described and as illustrated in Figures 4 and 5 of the accompanying
drawings.
Dated this 26th day of May 1899.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and 25, Cross Street, Manchester,
Agents.