IMPROVEMENTS IN APPARATUS FOR SIGNALLING ON RAILWAYS
Year: 1885

page_text: THOMAS TEALE POWELL of Harrogate in the County of York China and Glass
Merchant do hereby declare the nature of my invention for "IMPROVEMENTS IN
APPARATUS FOR SIGNALLING ON RAILWAYS" to be as follows :—
This Invention has for its object improvements in apparatus for signalling on
Railways.
In order that an electric signal may be given whenever a train passes along a
line of railway I provide at the place from which it is desired that the signal should
be transmitted apparatus which I will proceed to describe.
I provide a bex in which a spiral spring (similar to a buffer spring but lighter) is
contained. The box consists of two cast iron cylinders each closed at one end and
the one cylinder slides within the other. The lower cylinder is formed of a piece
with a base plate which is fixed beneath one of the rails along which the train
passes so that the upper cylinder which is sustained by the spring bears against the
under side of the rail. When a train passes along the line the rail yields and the
spring is to some extent compressed. An India rubber band excludes dust from
the joint of the spring box. The spring box contains paraffin oil, and some of this
is expelled by the collapsing of the spring box as the train runs over. The oil
passes out by an aperture near the bottom of the spring box into a passage
terminating in an upwardly directed nozzle contained in an oil cistern provided on
the same base plate with the spring box. The oil is spirted up through this nozzle
into a guide pipe by which it is directed away and caused to operate apparatus
hereinafter described. The nozzle is below the surface of the oil in the cistern and
when the train leaves the spring box, and allows it to resume its original dimensions
oil is sucked back from the cistern into the box. The oil when spirted up from
the jet is led by the guide pipe into a bowl carried by a lever. The lever can turn
about an axis or pivots and it does so turn when the oil enters the bowl, the
weight overcoming a counterpoise at the other end of the lever. The lever carries
a light arm and this when the lever moves with the weight of the oil dips down
into an insulated mercury cup connected with a circuit wire. There being
metallic contact between the lever and the other metallic parts of the apparatus
when the arm dips into the mercury cup the circuit of the line wire is closed.
Price 1171

page_text: A stop spring is also provided on the lever and when the lever moves with the
weight of the oil in the bowl this spring comes against an insulated stud connected
with the mercury cup and so a second contact is made.
The bowl is perforated at the bottom to permit the oil which it receives
gradually to escape into the cistern and then the lever returns by the action of
the counter poise to its original position. Oil can be supplied to the cistern from
time to time by means of a bird fountain filler or inverted bottle the mouth of
which dips into the liquid in the cistern when this contains the proper working
quantity. An over flow pipe may be provided if desired.
The circuit closer described above may advantageously be used in connection
with train signalling apparatus described in the specification of a former Patent
granted to me N° 1375. in the year 1878.

page_text: I THOMAS TEALE POWELL of Harrogate in the County of York China and
Glass Merchant 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 has for its object improvements in apparatus for signalling on
railways.
In order that an electric signal may be given whenever a train passes along a line
of railway I provide at the place from which it is desired that the signal should
be transmitted apparatus which I will proceed to describe.
I provide a box in which a spiral spring (similar to a buffer spring but lighter)
is contained. The box consists of two cast iron cylinders each closed at one end
and the one cylinder slides within the other. The lower cylinder is formed of a
piece with a base plate which is fixed beneath one of the rails along which the
train passes so that the upper cylinder which is sustained by the spring bears
against the under side of the rail. When a train passes along the line the rail and
road yields and the spring is to some extent compressed. An india rubber band
excludes dust from the joint of the spring box. An outer casing protects the band
from weather and mechanical injury. The spring box contains paraffin oil and
some of this is expelled by the collapsing of the spring box as the train runs over.
The oil passes out by an aperture near the bottom of the spring box into a passage
terminating in an upwardly directed nozzle contained in an oil cistern provided on
the same base plate with the spring box. The oil is spirted up through this nozzle
into a guide pipe by which it is directed away and caused to operate apparatus
hereinafter described. The nozzle is below the surface of the oil in the cistern and
when the train leaves the spring box and allows it to resume its original
dimensions oil is sucked back from the cistern into the box. The oil when spirted
up from the jet is led by the guide pipe into a bowl carried by a lever. The lever
can turn about an axis or pivots and it does so turn when the oil enters the bowl,
the weight overcoming a counterpoise at the other end of the lever. The lever
carries a light arm and this when the lever moves with the weight of the oil dips
down into an insulated mercury cup connected with a circuit wire. There being
metallic contact between the lever and the other metallic parts of the apparatus
when the arın dips into the mercury cup the circuit of the line wire is closed.
A stop spring is also provided on the lever and when the lever moves with the
weight of the oil in the bowl this spring comes against an insulated stud connected
with the mercury cup and so a second contact is made.
The bowl is perforated at the bottom to permit the oil which it receives gradually
to escape into the cistern and then the lever returns by the action of the counter-
poise to its original position. Or in place of the oil receptacle moving a float may
be provided within it or in the oil cistern and the float rising or falling as the
receptacle fills moves a lever and so in like manner makes the requisite electrical
contacts. Oil can be supplied to the cistern from time to time by means of a bird
fountain filler or inverted bottle the mouth of which dips into the liquid in the

page_text: cistern when this contains the proper working quantity. An overflow pipe may be
provided if desired.
The circuit closer described above may advantageously be used in connection
with train signalling annaratus described in the specification of a former patent
granted to me N° 1375 in the year 1878.
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.
granted to me N° 1375 in the year 1878.
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.
Figure 1 is a longitudinal section and Figure 2 is a plan with some parts removed
of an apparatus constructed in accordance with my invention for the transmission
of electrical signal currents on railways.
The
A A¹ is a box composed of two cylinders fitting one within the other and
containing a spiral spring B which sustains the inner cylinder A¹ and causes it to
abut upon the underside of the road rail C. D is a sleeve of vulcanized india
rubber connecting the head of the cylinder A¹ with the upper end of the cylinder A;
it serves to exclude dust-E is a passage connecting the cylinder A with an oil
cistern F, the passage opens into the cistern by a nozzle E³ from which, when the
cylinder A¹ is depressed (in consequence of the rail above it being deflected by a
train passing along the line) a jet of oil is spirted upwards-G is a directing pipe
through which this jet ascends. G¹ is an orifice by which the directing pipe
communicates with the cistern F. The oil in the cistern stands some distance
higher than the orifice G¹ and fills the lower part of the directing pipe. The
cistern is charged from the fountain oil feeder H the mouth of which enters the
branch passage F¹ on the side of the cistern F-F is an overflow pipe to ensure
that the piston shall not at any time be filled too full. I is a bowl with a
perforated bottom and over it a strainer formed of wire gauze closely woven.
bowl is mounted upon a lever I¹ turning upon a stud at 1%, and it is provided
with a counterpoise I sufficiently heavy to overbalance the weight of the bowl I
when empty. I³ is a metallic arm on the lever T-it carries a pin at its end and
this pin, when the bowl descends, dips into mercury contained within the cup K.
This cup is carried by an arm K¹ but is insulated from it by means of vulcanite or
other suitable insulating material. L is a line wire insulated by a covering of
gutta percha or in other convenient way; it enters into the interior of the cistern F
and is placed in metallic connection with the mercury cup K-I is a spring
attached to the lover I-when the bowl falls this spring comes against a stop M
carried by an arm M¹ but insulated from it. The stop M also is connected with
the line wire L. This stop serves two purposes-it mechanically arrests the
descent of the bowl when it has fallen sufficiently far, and it establishes a second
electrical contact as a precaution against any failure which may arise at the first
contact. Thus, as already explained, on the passage of a train along the line a jet
of oil is projected from the nozzle E' and this, together with a further quantity of
oil which it draws from the cistern and carries with it, ascends the directing pipe G
and falls into the bowl I. The weight of the oil immediately causes the bowl
to drop and the lever carrying it to tip, thereby bringing the point on the arm I³
down into the mercury contained in the cup K and also bringing the spring I*
against the stop M. Electrical connection is thus effected between the line wire L
and the earth through the lever 11, the metallic parts of the apparatus and the
rails of the railway line. The line wire forms part of a battery circuit and on
closing this circuit a signal current passes. N is a vent pipe by which the interior
of the cistern F is placed in free communication with the outer air.
Figure 3 is a longitudinal section and Figure 4 is a plan showing a modification
according to which a stationary receiver is substituted for the bowl or moveable
oil receptacle.
In this arrangement the jet of oil issuing from the nozzle E¹ passes together with
that which it takes from the cistern F up the guide pipe G as already described,

page_text: but in this case the oil falls into a stationary receiver i. instead of into the moving
bowl J. The partition F1 which separates the receiver from the other compartment
of the cistern F is perforated, and the perforations are small, so that when a
difference of level has been established on the two sides of the partition it is
some time before equalization takes place. J is a float on the surface of the oil in
the cistern Fit is carried by a lever J' and this is provided with arms J³ J³
and a spring J, the former when the float descends dipping down into mercury
cups, and the latter coming against an insulated pin and operating in the manner
already described in respect to the parts I³ and I' in Figures 1 and 2.
Figures 5 show details of the two mercury cups; one is simply fixed into the side
of the cistern and makes an earth connection and the other cup is insulated with
vulcanite washers.
Figure 6 is a longitudinal section showing another modification in which the
electric circuit is closed by the movement of a ram or plunger within a cylinder.
In Figure 6 the jet E' is dispensed with but the oil forced along the passage E
by the descent of the cylinder A¹ passes by a valve M into a cylinder N in which
a ram O is contained-0¹ is a contact stud on the top of the ram O and O' is a
wire passing from this stud to the walls of the cistern F to ensure a good electrical
connection-P is an insulated spring connected with the line wire. Qis a valve
by which oil is able to pass back from the cistern F into the passage E.
The action of this apparatus is as follows:-
When the cylinder A¹ is forced down by the passage of a train along the line,
oil passes by the passage E past the valve M into the cylinder N and the ram O,
rises. The stud O¹ and the spring Pare thus brought into contact and the electrical
current passes in the line wire. When the ram O, has risen as high as is desired
any further quantity of oil entering the cylinder N is able to pass freely away by
the aperture N' in the side of the cylinder, which then becomes uncovered.
After the passage of the train the cylinder A¹ rises by the operation of the
spring B, beneath it and oil is drawn from the cistern F into the passage E past
the valve so that the box or receptacle A. A¹ is kept constantly full of oil. The
ram O does not tightly fit the cylinder N but oil is able to find its way slowly out
past the ram, and the ram after it has been raised descends more or less slowly by
its own weight; the stud O', then passes out of contact with the spring P and the
circuit of the line wire L is again opened.
Sometimes it is desirable to provide for the completion of two separate circuits.
when a train runs past the apparatus; I provide for this case in the manner
indicated in Figure 7 which is a vertical section. The part A¹ here becomes a
piston with a rod passing upwards to the under side of the rail.
When the piston descends liquid is ejected from the cavity beneath it and when
it rises liquid is similarly ejected from the cavity above. The rest of the apparatus
being duplicated two separate circuits can be controlled.
Or the liquid from both cavities may be delivered into the same bowl or receiver
and co-operate to produce the movement of the contact lever or part.
Figure 8 is an elevation partly in section showing the means which I employ for
connecting the railway rails with the contact apparatus in cases where it is
inconvenient to place it immediately under one of the rails.
It is important to observe that in all these arrangements the electrical contact is
maintained for a definite time after the train has passed, and so a reliable signal
current through the line wire is obtained with certainty.
Figure 8 shows the way in which I arrange the apparatus when it cannot be
placed immediately beneath one of the rails. In this figure R. R. are the two rails
and S is a stiff metal bar firmly secured to them-it has an arm S' and on the
under side of this arm, where it is bent upwards, the head A³, of the cylinder A'
shown in the other figures is made to abut. A train passing along the line
depresses the two rails R. R equally and so the bar S¹, is carried downwards with
a parallel movement; in its descent it imparts the requisite movement to the
cylinder A¹.

page_text: By the means which I have described an efficient and reliable signal current is
made to pass along the line wire whenever a train passes over the rails. in the
neighbourhood of the signal apparatus and this signal current can be applied by
well known means as electrical signal currents have before been applied, either
simply to give an indication of the passage of the train or more commonly to
lock or to unlock or to permit or to prohibit the movement of signal and switch
levers.
"
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 I do
not confine myself to the exact details represented by the drawings but what
I claim is
1. Apparatus for transmitting electrical signal currents on railways in which the
road rail when deflected by the passage of a train moves a cylinder piston or part
and so ejects liquid from a box or vessel in which it is contained which liquid
then moves a contact lever or part controlling the passage of signal currents in a
line wire substantially as described.
2. Apparatus for transmitting electrical signal currents on railways in which a
train in passing along the road moves a cylinder piston or part and so ejects liquid
from a box or vessel in which it is contained through a nozzle; this jet of liquid
then passing together with other liquid which it puts into motion into a guide
passage leading to a receptacle where the retention of the liquid causes the move-
ment of a contact lever or part controlling the passage of signal currents in a line
wire substantially as described.
3. Appuratus for transmitting electrical signal currents on railways in which a
train in passing along the road moves a cylinder piston or part and so ejects liquid
from a box or vessel in which it is contained and causes the liquid to pass into a
counterpoised receptacle which thus being caused to move controls the passage
of signal currents in a line wire substantially as described.
4. Aparatus for transmitting electrical signal currents on railways substantially
as described and represented by the annexe'l drawings.