IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SWITCHES AND SIGNALS
Year: 1881

page_text: LETTERS PATENT to John Townsend Bucknill, Capt. in H.M. Corps of Royal
Engineers, and of Cockcrow Hill, Long Ditton, in the County of Surrey,
for an Invention of IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY
SWITCHES AND SIGNALS."
PROVISIONAL SPECIFICATION left by the said John Townsend Bucknill
at the Office of the Commissioners of Patents on the 10th January 1881.
JOHN TOWNSEND BUCKNILL, Capt. in H.M. Corps of Royal Engineers, and of
"IMPROVEMENTS IN
Cockcrow Hill, Long Ditton, in the County of Surrey.
APPARATUS FOR WORKING RAILWAY SWITCHES AND SIGNALS."
This Invention has for its object improvements in apparatus for working railway
switches and signals.
As railway switches and signals are now usually worked a considerable amount
of physical exertion is demanded of the signal man when it is required to actuate
switches or signals at a considerable distance from the signal cabin in which are
the hand levers and the interlocking gear. The distance at which the switches
and signals are placed is sometimes limited by this consideration.
Now according to my Invention I overcome this difficulty by the application of
hydraulic power in the following manner :-
I lead a pipe containing water or liquid under pressure from place to place,
wherever there is a switch or signal to be operated by the hydraulic gear. At
each of these points I provide an hydraulic cylinder or equivalent apparatus in
communication by rods and levers or like appliances with the switch or signal to
be moved, and I also provide at each place a cock or valve connected by a wire
with a corresponding hand lever in the signal cabin. By the movement of the
hand lever in the signal cabin (which is controlled by the interlocking gear in the
usual way) the cock or valve is placed so as to admit water under pressure into
the hydraulic cylinder, and thereby to cause the required movement of the switch
or signal to take place. I cause the water or liquid to be discharged from the
cylinders into another pipe, which accompanies the pressure pipe wherever it may
be led; thus the same liquid may be used again and again, which is important
when it is necessary to employ an unfreezable liquid. The movement of the liquid

page_text: in the flow or return pipe can be utilized to indicate that the switch or signal
Where certain switches
actually follows upon the movement of the hand lever.
and levers always require to be moved at the same time I operate them all by
means of one hand lever giving movement by several connecting wires to the
cocks or valves of several hydraulic cylinders, or where the switches and signals
to be operated are not remote from one another I couple two or more by means of
rods and levers or like connections in the case of switches, and by means of wires
in the case of signals, to one hydraulic cylinder, which, if need be, may be of larger
size than the cylinders which have but one office to perform, and generally each
cylinder can be of proportionate dimensions to the work to be done, points requiring
larger cylinders than signals.
Where it is desirable to effect a further reduction in the amount of physical
exertion demanded of the signal man, or a further increase in the distance at which
points and signals may be worked in the aforesaid manner, I arrange the hand
levers to operate cocks or valves controlling the admission of water under pressure
to other hydraulic cylinders for working the wires, by which in turn the cocks or
valves of the distant hydraulic cylinders are controlled.
In a similar manner I arrange automatic gear to work signals on the block
system. On this system the signal is put to danger on the passage of a train, and
is not lowered until the train has passed the next signal post; or, better still, has
passed two signal posts in advance. For this purpose I cause the train in passing
to move a tappet in connection with a cock or valve controlling the passage of
water from the pressure pipe into an hydraulic cylinder. The hydraulic cylinder
operates to raise the signal, and at the same time the same cylinder or another
hydraulic cylinder moves a wire passing back to another signal post, and there
shifts the cock or valve so as to cause the back signal to be taken off..
distance be too long to be worked direct the wire passes back to a cock or valve
belonging to an intermediate or relay cylinder, which in turn gives movement to
another wire working the cock or valve controlling the cylinder, by which the
back signal is actually operated. Or when necessary more than one intermediate
or relay apparatus may be applied.
Or if the

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Townsend Bucknill in the Great Seal Patent Office on the
9th July 1881.
JOHN TOWNSEND BUCKNILL, Captain in H.M. Corps of Royal Engineers, and of
Cockcrow Hill, Long Ditton, in the County of Surrey.
APPARATUS FOR WORKING RAILWAY SWITCHES AND SIGNALS."
"IMPROVEMENTS IN
}
This Invention has for its object improvements in apparatus for working railway
switches and signals.
As railway switches and signals are now usually worked a considerable amount
of physical exertion is demanded of the signal man when it is required to actuate
switches or signals at a considerable distance from the signal cabin in which
are the hand levers and the interlocking gear. The distance at which the switches
and signals are placed is sometimes limited by this consideration.
Now according to my Invention I overcome this difficulty by the application of
hydraulic power in the following manner :-
At
I lead a pipe containing water or liquid under pressure from place to place,
wherever there is a switch or signal to be operated by the hydraulic gear.
each of these points I provide an hydraulic cylinder or equivalent apparatus in
communication by rods and levers or like appliances with the switch or signal to
be moved, and I also provide at each place a cock or valve connected by a wire
with a corresponding hand lever in the signal cabin. By the movement of the
hand lever in the signal cabin (which is controlled by the interlocking gear in the
usual way) the cock or valve is placed so as to admit water under pressure into
the hydraulic cylinder, and thereby to cause the required movement of the switch
or signal to take place. I cause the water or liquid to be discharged from the
cylinders into another pipe which accompanies the pressure pipe wherever it may
be led; thus the same liquid may be used again and again, which is important
when it is necessary to employ an unfreezable liquid. The movement of the liquid
in the flow or return pipe can be utilized to indicate that the switch or signal
actually follows upon the movement of the hand lever. Where certain switches
and levers always require to be moved at the same time I operate them all by
means of one hand lever, giving movement by several connecting wires to the
cocks or valves of several hydraulic cylinders; or where the switches and signals
to be operated are not remote from one another I couple two or more by means of
rods and levers or like connections in the case of switches, and by means of wires in
the case of signals, to one hydraulic cylinder, which, if need be, may be of larger
size than the cylinders. which have but one office to perform, and generally each
cylinder can be of proportionate dimensions to the work to be done, points requiring
larger cylinders than signals.
Where it is desirable to effect a further reduction in the amount of physical
exertion demanded of the signal man, or a further increase in the distance at
which points and signals may be worked in the aforesaid manner, I arrange the
hand levers to operate cocks or valves controlling the admission of water under
pressure to other hydraulic cylinders for. working the wires, by which in turn the
cocks or valves of the distant hydraulic cylinders are controlled.
In a similar manner I arrange automatic gear to work signals on the block
system. On this system the signal is put to danger on the passage of a train, and
is not lowered until the train has passed the next signal post, or, better still, has
passed two signal posts in advance. For this purpose I cause the train in passing
to move a tappet in connection with a cock or valve controlling the passage of
water from the pressure pipe into an hydraulic cylinder. The hydraulic cylinder

page_text: operates to raise the signal, and at the same time the same cylinder or another
hydraulic cylinder moves a wire passing back to another signal post, and there
shifts the cock or valve so as to cause the back signal to be taken off; or if the
distance be too long to be worked direct the wire passes back to a cock or valve
belonging to an intermediate or relay cylinder, which in turn gives movement to
another wire working the cock or valve controlling the cylinder by which the back
signal is actually operated; or when necessary more than one intermediate or
relay apparatus may be applied.
In order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
DUCIS appoor wowo jur
operates to raise the signal, and at the same time the same cylinder or another
hydraulic cylinder moves a wire passing back to another signal post, and there
shifts the cock or valve so as to cause the back signal to be taken off; or if the
distance be too long to be worked direct the wire passes back to a cock or valve
belonging to an intermediate or relay cylinder, which in turn gives movement to
another wire working the cock or valve controlling the cylinder by which the back
signal is actually operated; or when necessary more than one intermediate or
relay apparatus may be applied.
In order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Sheet I., Figure 1, represents in sectional elevation an ordinary signal man's
cabin fitted with the hydraulic gear, already described in general terms.
A is the accumulator, which will be described in detail directly.
W is the weight lifted by accumulator.
P is the hand pump, to be described in detail directly; the inflow to the cistern
of this pump is connected to
F, the funnel tell tale, which is placed in front of the signal man, by
b, a small pipe.
a, another small pipe, supplies the cylinder of the accumulator from the
pump.
c, another small pipe, connects the accumulator with all the hydraulic
cylinders.
, another small pipe, brings the fluid back from the various cylinders, and
terminates in a bend over the funnel F, with which it thus forms a tell tale. If
'desired a small tumbling tumbler g may be placed, as indicated by Figures 1ª,
between the end of the pipe d and the funnel F, the capacity being equal to that
of each of the cylinders employed, and the tumbler only tumbling and emptying
itself into the funnel when the tumbler is full, the tumbling being automatic.
In some situations however it may be convenient to employ cylinders of different
capacities, the capacity of each being made to correspond with the work it has to
perform. Moreover the automatic tumbler is hardly required in any case, as the
signal men will soon learn to judge accurately, when they see the liquid flow,
whether the action has been as usual.
The tell tale, as shown in the Drawings, forms a test which is applied every time
the apparatus is used, and thus informs the signal man that everything is in
working order.
The lever L is one of those employed to actuate the switches and signals at a
distance. It is in connection by a wire and rods and levers or pulleys with the
cock or valve of an hydraulic cylinder at the distant place. The arrangement is as
follows: The vertical rod descending from the lever is connected with an arm s
on the leading off axle T, and this arm is cranked, the other part being connected
with the wire which leads to the distant hydraulic cylinder.
Figure 2 represents one of the distant hydraulic cylinders fitted to actuate a
double pair of points, a single pair only being shown on the Drawing, the other
pair being moved by the rod r in the usual manner, and as shown on Figure 3.
H, Figure 2, represents the plan of the cover of the cylinder; c, c, the high pressure
pipe; d, d, the low pressure return pipe; and w, the wire which moves the arm a
connected to the cock or valve of the hydraulic cylinder. As soon as the wire wis
pulled in the direction indicated by arrow, the cock or valve is moved, and the
piston rod p of the hydraulic cylinder is thrust out, moving the points shown in
In the
the Drawing, as well as the more distant points connected by rod r.
Drawings, in which I represent the hydraulic cylinder in detail, a slide valve is
represented to control the entrance and exit of the water or fluid, but a cock or
rotating valve might be used. The valve is so arranged that when the wire w is

page_text: released at the signal station the pressure of the liquid on the valve itself draws
the wire back into what may be termed the normal position, thus actuating the
piston in the cylinder for a return stroke, and thus also bringing the points back
to the normal position. The details of the hydraulic, cylinders and valves will be
explained directly. The lever L', in Figure 1, moves the valve of an hydraulic
cylinder H within the cabin, and the piston rod of this cylinder is connected with
a rod or a wire for working a gate, switch, or signal.
The levers L, L, Figure 1, are arranged with interlocking gear as usual. In
order to prevent the signal man moving his handle at all if the accumulator become
empty a rod r is carried back from each of the cranks on the leading off axle T
which is connected with a hydraulic cylinder, and the rods are made of such a
length and are carried in such a direction that when W comes to the ground it
firmly holds the said rods r and locks the levers L, L¹, etc., and all the other levers
which are in connection with the hydraulic gear, either in the signal box or out
of it.
Figure 3 shows the general arrangement in plan of a small railway station, one
half of the points, etc., only being shown.
P is the pump; A, the accumulator; and H., H, are two hydraulic cylinders in
the signal cabin actuating the two distant signals S, S', the former S only being
shown on the Drawing. The two hydraulic cylinders H, H, actuate the points a, a¹,
and b, b, respectively.
The dotted line
--
represents the high pressure pipe, the chain dotted
the low pressure pipe, and the chain dotted line
line
represents the wires which actuate the valves of the hydraulic cylinders. To
simplify the Drawings the wires are not all indicated, but all the pipes are shown.
The home and other signals within 300 or 400 yards of the cabin are shown as
being moved (as at present) by wires direct from the levers in the signal cabin, but
the hydraulic gear can if desired be applied to each signal as well as to each point
in the station.
Sheet 2, Figure 4, represents the longitudinal section, Figure 5 the cross section,
Figure 6 the end view, and Figure 7 the plan of one of the hydraulic cylinders.
In Figure 4 the piston is shown with full pressure on the end remote from the
piston rod, the piston being firmly pressed against the cylinder cover with a total
pressure of about one ton. The piston, which is double acting, is provided with
two leather cup washers, and the details of the cylinder and piston, and piston rod,
and cast iron foot plate, and guide, and glands, and packings, and channels, and
valve, and valve box, and cover for valve box, and cover for the whole to protect it
from dirt and dust are shewn with sufficient clearness upon the Drawings,
Figures 4, 5, 6, 7.
The high pressure junction pipe c comes in on one side, and the low pressure
pipe d goes out on the other. The valve rod is made large as shewn in order that
the pressure of the liquid which fills the valve chamber may push the valve and the
valve lever with its wire to signalman's cabin back into their normal position as
soon as the signal man releases the hand lever L (see Figure 1, Sheet I.)
In those situations where there is a considerable length of wire between the
signal cabin and the hydraulic cylinder, and consequently increased friction, it may
then become necessary to supplement the above return action by the usual weight
on lever or weight over pulley to help to draw back the wire from signal cabin as
soon as the signalman releases it.
Figure 8, Sheet 2, represents the section of the hand pump for a small station,
as shewn on the Figure 3, Sheet I., but in larger and more important stations it will
be preferable to employ a small motor (such as a small gas engine or a caloric
engine) for the purpose of keeping the accumulator charged. This motor and
accumulator might then be placed at any convenient position, and not necessarily
in or even near to the signal cabin, but it is better to place such motor and
accumulator in or near to the signal cabin in order that the signal man may have
proper control over the driver, and in order that the weight of the accumulator

page_text: may act as already described to lock the levers when the pumping is neglected.
Again, the motor and pump may be separated from the accumulator, but it is
preferable to keep them together.
The hand pump and cistern shewn in Figure 8 calls for no special remark. The
supply pipe from the funnel tell tale may be led in at the top of the cistern, which
can be made open as shewn in Figure 13, the top being only a cast iron bar to
carry the pump gear.
Figures 9, 10, 11, 12, represent the accumulator, which has been drawn so as to
fit into an ordinary cabin, the weight being under the top story.
The chains are fixed at one end to the lugs a, b, on the casting of cylinder of
accumulator, Figure 9, and at the other end to the weight by the eyes a¹, b¹, (see
Figure 11). The chains pass through the holes a, b, in the foot plate of the
accumulator as shewn in Figure 12.
The weight, Figure 11, is arranged in the manner shewn so that the pressure
can be increased when desired, the cavity being filled with old railway chairs of..
cast iron or with other convenient and ponderous articles. The weight shewn on
Figure 11 will, when combined with the accumulator shewn on the other
Figures 9, 10, 12, produce a pressure of about 350 lbs. on the square inch, and by
filling it up with iron rubbish the pressure can be raised to 700 lbs. on the square
inch. There is an advantage in possessing this power to alter the pressure at will
without great trouble, because in summer the wires and rods can be moved more
easily than in winter when snow and ice choke everything,
And this leads to the important question of what liquid to use in order that it
may not become frozen during severe frosts. After much investigation I prefer
glycerine and water mixed in equal proportions. This only freezes at temperatures.
far lower than those met with in England or even in Canada, but other non freezing
liquids may be used, and in hot climates water may be used.
As regards the manner in which the pipes should be laid, inasmuch as the pipes
are small, they can be laid above ground on suitable stumps, and they will then
last longer, and any leakage be more easily rectified; in such a case expansion and
contraction must however be provided for when the pipes are carried for some
distance. I prefer to do this by means of a spiral about 2 feet diameter inserted at
suitable intervals. That portion of the pipe near to the cylinders should be firmly
secured to the ground by sleepers, etc., so that the expansion of the pipes in hot
weather may not strain the holding down bolts of the hydraulic cylinders.
THE AUTOMATIC GEAR.
The automatic arrangements have already been described in general terms. It
is shewn by the Figures 14, 15, 16, 17, and 18.
The action desired is as follows:-The train is to put each signal at danger on
passing it, and to lower the back signal at the same instant, the signal in front of
the train, and the second signal back, not being moved by the above action.
For this purpose I place at each signal post one of the hydraulic cylinders H
before described, a high and a low pressure pipe being led to each cylinder as
explained.
The valve of each cylinder is moved by a cam on an axle, which latter is actuated
in one direction by the movement of an end lever e, which is struck over on the
passage of an engine on the line, and in the other direction by the movement of a
lever g on the other end of the axle, which is moved by a tappet pivotted on a
sliding bar, Figure 18.
Figures 14, 15, 16, show three signal posts and the required arrangements for
automatic working, but it should be understood that the gear can be placed on the
ground. It is raised in the Drawings in order to make the parts more easily
discerned.
In Figure 15 the engine lever e is in the act of being moved by a passing
engine.
This causes an outward movement of the piston rod, and by this the signal is

page_text: raised to indicate that a train has passed onto the line. It also causes the wire w
leading back to the last signal post to be pulled, which brings about the fall of
the signal at this post.
On examination it will be found that'g is only actuated by the movement of the
sliding bar connected to the wire from the advanced signal when that wire is pulled.
When it is slacked off the tappet (see Figure 18) turns down without actuating the
lever g.
The arrangement also entirely disconnects the wire from the valve
spindle, which is actuated suddenly by a passing engine. It will be noticed that
the amplitude of the movement of the sliding bar is greater than the amplitude of
the sweep of the end of arm g.
Figure 17 shews the plan of the arrangement.
The engine strikes the lever e, actuates pistons in a plus direction, puts signal to
danger, and draws the wire to the last cylinder, which is thus actuated in a minus
direction, and the back signal lowered, and this action is done without moving the
other signals.
The valve rod of the hydraulic cylinders used for this automatic working must
be reduced from that shewn in Figure 4, and a weight or spring balance introduced
to counteract the thrust of the liquid pressure upon the action of the valve rod,
because the valve should lie indifferently in whichever direction the tumbling cam
placed it. Or the valve spindle may pass by a gland through each end of the
valve box.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim,-
First. The combination of apparatus for working railway switches and signals
from a distance, consisting of (1), hydraulic cylinders or equivalent apparatus in
the vicinity of the switches or signals, and serving directly to operate the same;
(2), pipes conveying water or fluid under pressure to the said cylinders or apparatus
from an accumulator or other source of supply; (3), cocks or valves permitting the
water or fluid under pressure to enter the said cylinders or apparatus, and at the
proper time to escape; (4), wires or like connections passing from the said cocks or
valves to the cabin or place to be occupied by the signalman, such wires when
pulled and released moving the cocks or valves, or permitting them to move; (5),
switch or signal levers or handles connected with the said wires either directly or
through the intervention of other hydraulic cylinders or apparatus.
Second. In the combination with the apparatus mentioned above, I claim the
funnel indicator and the return pipes leading back thereto the water or fluid
discharged from the hydraulic cylinders or apparatus.
Third. My automatic block signal apparatus, consisting of (1) hydraulic cylinders
or equivalent apparatus in the vicinity of the signals, and serving directly to
operate the same, and also wires passing back from signal to signal; (2), pipes
conveying water or fluid under pressure to the said cylinders or apparatus; (3),
cocks or valves permitting the water or fluid under pressure to enter the hydraulic
cylinders or equivalent apparatus, and at the proper time to escape; (4), levers or
like instruments acted on by the passing trains, and causing the movement of the
cocks or valves which results in raising the signals or setting them to danger;
(5), wires or equivalent connections passing back from signal to signal, which being
moved by the hydraulic cylinders or equivalent apparatus, transmit the movement
back to the valves, causing the signals to fall or assume the position which indicates
that the line is clear.
In witness whereof, I, the said John Townsend Bucknill, have hereunto set
my hand and seal, this Eighth day of July, in the year of our Lord One
11
J. T. BUCKNILL, CAPT. R.E. (L.S.)