Improvements in Railway Signalling Apparatus.
Year: 1896

page_text: Date of Application, 30th Nov., 1896-Accepted, 7th Aug., 1897
COMPLETE SPECIFICATION.
Improvements in Railway Signalling Apparatus.
I, WILLIAM THOMAS CASSEL PRATT, of 10 Downleaze, Sneyd Park, Clifton,
Bristol, in the County of Gloucester, l'hysician, do hereby declare the nature of this
invention and in what manner the same is to be performed, to le particularly
described and ascertained in and by the following statement:-
This invention relates to improvements in the railway signalling apparatus
described in the Specification of my Patent No. 15023, dated 7th August 1894.
The object of this my present invention is first, to so connect those parts of my
aforesaid apparatus which are carried by or fitted on or to the locomotive as to
remove or minimise the tensional or other strain caused by the weight of said parts
on the whistle spindle or other movable part to which the apparatus is connected;
secondly, to provide means whereby after the cutting or rupture of the ring or
frame by the knife or cutter fixea on or adjacent to the permanent way, another
such ring or frame shall automatically fall into position ready for the next adjust-
ment of the various parts in the set position by the driver or other person in charge
of the engine; and, thirdly, to adapt the knife or cutter to be operated otherwise
than from the signal box.
In the accompanying drawings Fig. 1 is a side elevation showing part of a rail-
way track and an engine and tender with my invention fitted thereto and on one
side thereof; Fig. 2 is a vertical section taken on the line az of Fig. 1; Figs. 3
and 4 are enlarged detached side and end elevations of those parts of my apparatus
which are carried by or fitted on or to the locomotive: Figs. 5 to 8 are further
enlarged detail views; and Figs. 9 to 11 show modifications of my invention all
of which will be more fully explained hereinafter. The same letters of reference
where thev occur are used to indicate the same or corresponding parts in all the
figures.
To carry out the first part of this my present invention I construct and arrange
the parts in the manner shown in Figs. 1 to 6 of the accompanying drawings. A
is the vertical rod to the lower end of which is fixed a radial hook or horn shaped
arm B (see Figs. 3, 4 and 6) which, when the apparatus is in the set position, rests
on the ring or frame in the manner described in my aforementioned Patent Speci-
fication. Near its upper end this rod A. is square in cross section, as shown at a,
Fig. 5, and for the rest of its length the said rod is of circular section. C is a
horizontal bracket which is rigidly affixed to or is integral with the side of the
cab or tender or other part of the locomotive and is provided with a square aper-
ture of corresponding size to the squared section a on the rod and through this
aperture the rod A nasses. Above the squared section a of the rod A is a short
cylindrical section a¹ above which are two fixed collars A' A'; and a fixed arm or
handle A3 (see Fig. 5) is situated at or near its top and so as to be within easy
reach of the driver or other person in charge of the engine. Between the
collars A A is linked one arm of a lever D (see Figures 3 and 4) having a centre
of motion at D¹ on the cab or other fixed part of the engine, and provided with a
counter-weight D which latter is nearly heavy enough to balance the parts on the
other side of the fulcrum D'. On the side of the lever D to which the vertical

page_text: rod A is connected, the lower end of a link E is pivotted, its upper end being
pivotted to one arm of a lever F having a fixed centre of motion at F and bifur-
cated at its other end as shown at F in Figs. 1 and 3. Between the furcations
at is pivotted one arm of a bell-crank lever G having a fixed centre of motion
at G and connected by the link H to another bell-crank lever J turning on a
fixed centre J (see Figs. 2 and 4). The free end J2 of this bell-crank J is bifur-
cated and the furcations thereof lie one above and the other below the handle k
fixed on the spindle of a plug cock or valve K in the branch steam pipe K
leading to the steam whistle K (see Fig. 2).
The action of this part of the apparatus will now be understood. When the
vertical rod A falls, in the manner to be explained hereinafter, the arm of the
lever is drawn down against the counterweight and the motion is trans-
mitted through the system of links and levers E, F, G and H to the bell-crank J
the bifurcated end J of whien is depressed thereby turning the handle & through
a downward angle of about 45° and opening the valve to that extent, which is
sufficient to allow the steam to pass to the whistle. By this construction the weight
of the rod A and its connections is carried by the fixed centres D F G and J
and consequently there is no undue strain on the spindle of the valve K. To return
the parts to the normal position shown in the drawings, the driver or other person
in charge rotates the rod A through an angle of 90 by means of the handle A
thereon. In falling the rod A has passed so far that the square section thereon
has passed completely through the squared aperture in the bracket C, consequently
the cylindrical section a' on the rod lies in said square aperture and can be easily
turned therein. When the rod has been turned through a right angle as before
said the radial hook arm B is clear of the path of the rings or frames. The rod A
is then raised until the squared section is above the square aperture in the
bracket C, it is then turned back again through a right angle to bring the arm B
to the full position saown in Fig. 6 when the rod A is gently lowered until the
arm B rests upon the base of the ring or frame which has fallen into the lowest
position in the manner to be explained hereinafter; the parts are then again in
the set position shown in Figs. 1 to 4.
The squared section a of the rod A keeps the latter steady in position against
the vibration set up by the motion of the engine when travelling.
When it is desired to sound the whistle during the running of the locomotive,
this can be effected by the driver raising the rod slightly above the normal posi-
tion shown in the drawings. This will have the effect of operating the system of
links and levers in an opposite direction to that already described, causing the
bifurcated end J of the bell-crank J to be raised sufficiently to turn the handle k
through an upward angle of about 45° which again will allow sufficient way for
the passage of steam through the valve to the whistle.
It will be understood that instead of operating the valve of the whistle, the
mechanism hereinbefore described may be connected to the gong of a bell, or may
be made to complete an electrical circuit containing a bell fixed on the cab of the
locomotive, or may be otherwise connected so as to give an audible or other
signal, to the driver or other attendant in or on the train, every time the rod A 4
falls below the normal set position.
To carry out the second part of this my present invention I make the rings
or frames which are cut or ruptured by the knife or cutter fixed on or adjacent to
the permanent way, of such a shape that they may be placed in a series one above.
the other, cach said frame supporting the one immediately above it, consequently 5
when the lowermost is cut or broken and falls on the track, the next lowermost
will by virtue of its own weight and that of the others superimposed upon it, fal!
into proper position ready to act as a support to the radial arm B when the appara-
tus is adjusted to the set position: all the superimposed rings or frames of course
falling down one step in the series.
Fig. 7 is a perspective view and Fig. 8 a plan of a ring frame suitable for the
5

page_text: purpose, although I do not confine myself to the particular shape therein shown,
all that is necessary being that it shall be sufficiently rigid, have a base made of an
easily separable material, preferably copper, and be furnished with vertical limbs
or members supporting an upper section large enough to form a foundation for the
base of the next frame above. In the form shown the base m is made in the shape
of an oval ring, in which are four posts m' arranged in pairs near the ends of the
rieg, each pair carrying a flanged top section me so made as to support the base of
the frame above. Fig. 6 shows the position of the knife or cutter L on the track
relatively to the separable base m of the frame. The height of the posts m' is
made so that the knife or cutter L will only cut the base of the lowermost frame as
shown in Fig. 2. These ring-shaped frames are passed through a U shaped hori-
zontal frame N and threaded on a central vertical guide-frame N' open in the
centre at the bottom, so that the knife may pass through; both frames N and N
being bolted on otherwise secured to a convenient part of the engine. The
frame N is provided with a collar or collars N at its lower end so situated as to
support the lowermost ring-frame in such a position that its base will be severed
by the knife or cutter L.
The action of this part of the apparatus is as follows:-when the travelling
train arrives at a knife or cutter I raised in the operative position, the separable
base m of the ring frame is cut or severed and falls from the guide frame on to the
track, thereupon the support being removed from the radial arm B, the rod A
falls and the mechanism on the locomotive is set off and the signal given in the
manner above described.
Although I have shown and described my invention as applied to one side of the
locomotive and the track it may be adapted to either or to both sides, or centrally,
if so desired, the method of adaptation being easily understood by persons having a
knowledge of railway engineering.
In Figs. 1 and 2 I have shown the knife or cutter L fitted to. be operated from
the signal box, by the ordinary signal lever connections, the knife or cutter L
being raised to the operative position by means of the counterweight on the
bell crank lever O which latter is fast on a horizontal arm L' to which the knife
or cutter L is fixed. The knife is lowered to the horizontal "all clear" position by
a pull on the signal lever. The arrows in Fig. 1 show the direction of the pull of
the signal lever and the direction of travel of the locomotive respectively. When
the pull on the signal lever is released the counterweight returns the knife to the
vertical operative position shown in th drawings. The travel of the knife or cutter
is only through an angle of 90° from the horizontal position to the vertical, and so
that when raised the knife is perfectly rigid.
In Fig. 9 I have shown how the knife L may be operated by a gate on a level
crossing so that when the gate is open to allow the passage of vehicles &c. across
the track the knife or cutter L connected to the gate shall be in the raised opera-
tive position, and lowered again when the gate is closed. This is effected by
simply connecting the lever O to an arm P on the gate P and at right angles
thereto, and near the hinge or pivot P on which the gate P2 turns. In the figure
the gate is shown open across the track and the knife, which is placed a suitable
listance away to allow the train to be brought to a stand still before it reaches the
rate, is raised. Instead of being connected to the gate the knife mechanism may
be connected to some part of a bridge or other structure so as to bring the knife
o the operative position when the structure collapses.
In Fig. 10 I have shown the knife connected to the points of a track so as to be
aised to the operative position when the points are open and lowered when the
oints are closed and therefore safe for the train to travel thereover.
ffected by connecting the lever O to the bell crank 1 by which the points are
This is
perated.
In Fig. 11 I have shown a modified form of a knife or cutter adapted to be fitted
y platelayers or others to signal to an approaching train to stop. In this case

page_text: the knife is a double edged one, and is permanently fixed in a vertical position on
a foot or base L' which latter is fitted with a thumb or other screw L³ to form a
clamp by which it may be temporarily secured to a sleeper L*.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
1. In railway signalling apparatus of the kind in which a knife or cutter fitted
on or adjacent to the permanent way severs a frame carried on the locomotive
thereby removing a support from a rod which falls by gravity and operates the
signal on the train, connecting said rod to the whistle or other signalling device
to be operated, by the system of levers hereinbefore described and illustrated in
Figs. 1 to 6 of the accompanying drawings and for the purpose stated.
2. In railway signalling apparatus of the kind indicated in the preceding claim,
making the ring frames each with a top section to support the base of another
when placed upon it, and arranging, the ring frames in suitable guides as to
rest one upon the other substantially as described and illustrated by way of
example in Figs. 1 to 4 and 7 and 8 of the accompanying drawings and for the
purpose stated.
3. In railway signalling apparatus of the kind indicated in claim 1 hereof, the
modified form of knife to be fixed to any one of the sleepers on the track shown and
described with reference to Fig. 11 of the accompanying drawings and for the
purpose stated.
4. Railway signalling apparatus consisting of a separable frame supporting
signalling mechanism on the train in combination with a knife or cutter fixed on
or adjacent to the permanent way and brought into operative position in any of the
ways hereinbefore described with reference to the accompanying drawings and for
the purposes stated..
F. W. GOLBY,
36 Chancery Lane, London, W.C., Patent Agent for the Applicant.